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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M . C H 8 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2013, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Fname; use Fname;
with Freeze; use Freeze;
with Impunit; use Impunit;
with Lib; use Lib;
with Lib.Load; use Lib.Load;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Namet.Sp; use Namet.Sp;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Cat; use Sem_Cat;
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_Ch13; use Sem_Ch13;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Eval; use Sem_Eval;
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 Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Sem_Ch8 is
------------------------------------
-- Visibility and Name Resolution --
------------------------------------
-- This package handles name resolution and the collection of possible
-- 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 potentially 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 re-chained 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 Analyze_Renamed_Primitive_Operation
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- If the renamed entity in a subprogram renaming is a primitive operation
-- or a class-wide operation in prefix form, save the target object,
-- which must be added to the list of actuals in any subsequent call.
-- The renaming operation is intrinsic because the compiler must in
-- fact generate a wrapper for it (6.3.1 (10 1/2)).
function Applicable_Use (Pack_Name : Node_Id) return Boolean;
-- Common code to Use_One_Package and Set_Use, to determine whether use
-- clause must be processed. Pack_Name is an entity name that references
-- the package in question.
procedure Attribute_Renaming (N : Node_Id);
-- Analyze renaming of attribute as subprogram. The renaming declaration N
-- is rewritten as a subprogram body that returns the attribute reference
-- applied to the formals of the function.
procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
-- Set Entity, with style check if need be. For a discriminant reference,
-- replace by the corresponding discriminal, i.e. the parameter of the
-- initialization procedure that corresponds to the discriminant.
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_In_Previous_With_Clause
(N : Node_Id;
Nam : Node_Id);
-- N is a use_package clause and Nam the package name, or N is a use_type
-- clause and Nam is the prefix of the type name. In either case, verify
-- that the package is visible at that point in the context: either it
-- appears in a previous with_clause, or because it is a fully qualified
-- name and the root ancestor appears in a previous with_clause.
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 proper scope table entry. This is usually the current scope, but it
-- will be an inner scope when installing the use clauses of the private
-- declarations of a parent unit prior to compiling the private part of a
-- child unit. This chain is traversed when installing/removing use clauses
-- when compiling a subunit or instantiating a generic body on the fly,
-- when it is necessary to save and restore full environments.
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 Has_Private_With (E : Entity_Id) return Boolean;
-- Ada 2005 (AI-262): Determines if the current compilation unit has a
-- private with on E.
procedure Find_Expanded_Name (N : Node_Id);
-- The input is a selected component known to be an expanded name. Verify
-- legality of selector given the scope denoted by prefix, and change node
-- N into a expanded name with a properly set Entity field.
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.
function Has_Implicit_Operator (N : Node_Id) return Boolean;
-- N is an expanded name whose selector is an operator name (e.g. P."+").
-- declarative part contains an implicit declaration of an operator if it
-- has a declaration of a type to which one of the predefined operators
-- apply. The existence of this routine is an implementation artifact. A
-- more straightforward but more space-consuming choice would be to make
-- all inherited operators explicit in the symbol table.
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.
function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
-- Prefix is appropriate for record if it is of a record type, or an access
-- to such.
function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
-- True if it is of a task type, a protected type, or else an access to one
-- of these types.
procedure Note_Redundant_Use (Clause : Node_Id);
-- Mark the name in a use clause as redundant if the corresponding entity
-- is already use-visible. Emit a warning if the use clause comes from
-- source and the proper warnings are enabled.
procedure Premature_Usage (N : Node_Id);
-- Diagnose usage of an entity before it is visible
procedure Use_One_Package (P : Entity_Id; N : Node_Id);
-- Make visible entities declared in package P potentially use-visible
-- in the current context. Also used in the analysis of subunits, when
-- re-installing use clauses of parent units. N is the use_clause that
-- names P (and possibly other packages).
procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False);
-- Id is the subtype mark from a use type clause. This procedure makes
-- the primitive operators of the type potentially use-visible. The
-- boolean flag Installed indicates that the clause is being reinstalled
-- after previous analysis, and primitive operations are already chained
-- on the Used_Operations list of the clause.
procedure Write_Info;
-- Write debugging information on entities declared in current scope
--------------------------------
-- 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
Check_SPARK_Restriction ("exception renaming is not allowed", N);
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;
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
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;
Analyze_Dimension (N);
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 : constant Entity_Id := Defining_Entity (N);
Old_P : Entity_Id;
Inst : Boolean := False; -- prevent junk warning
begin
if Name (N) = Error then
return;
end if;
Check_SPARK_Restriction ("generic renaming is not allowed", N);
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_Is_Pure (New_P, Is_Pure (Old_P));
Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
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;
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, New_P);
end if;
end Analyze_Generic_Renaming;
-----------------------------
-- Analyze_Object_Renaming --
-----------------------------
procedure Analyze_Object_Renaming (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Id : constant Entity_Id := Defining_Identifier (N);
Dec : Node_Id;
Nam : constant Node_Id := Name (N);
T : Entity_Id;
T2 : Entity_Id;
procedure Check_Constrained_Object;
-- If the nominal type is unconstrained but the renamed object is
-- constrained, as can happen with renaming an explicit dereference or
-- a function return, build a constrained subtype from the object. If
-- the renaming is for a formal in an accept statement, the analysis
-- has already established its actual subtype. This is only relevant
-- if the renamed object is an explicit dereference.
function In_Generic_Scope (E : Entity_Id) return Boolean;
-- Determine whether entity E is inside a generic cope
------------------------------
-- Check_Constrained_Object --
------------------------------
procedure Check_Constrained_Object is
Typ : constant Entity_Id := Etype (Nam);
Subt : Entity_Id;
begin
if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
and then Is_Composite_Type (Etype (Nam))
and then not Is_Constrained (Etype (Nam))
and then not Has_Unknown_Discriminants (Etype (Nam))
and then Expander_Active
then
-- If Actual_Subtype is already set, nothing to do
if Ekind_In (Id, E_Variable, E_Constant)
and then Present (Actual_Subtype (Id))
then
null;
-- A renaming of an unchecked union has no actual subtype
elsif Is_Unchecked_Union (Typ) then
null;
-- If a record is limited its size is invariant. This is the case
-- in particular with record types with an access discirminant
-- that are used in iterators. This is an optimization, but it
-- also prevents typing anomalies when the prefix is further
-- expanded. Limited types with discriminants are included.
elsif Is_Limited_Record (Typ)
or else
(Ekind (Typ) = E_Limited_Private_Type
and then Has_Discriminants (Typ)
and then Is_Access_Type (Etype (First_Discriminant (Typ))))
then
null;
else
Subt := Make_Temporary (Loc, 'T');
Remove_Side_Effects (Nam);
Insert_Action (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Subt,
Subtype_Indication =>
Make_Subtype_From_Expr (Nam, Typ)));
Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
Set_Etype (Nam, Subt);
end if;
end if;
end Check_Constrained_Object;
----------------------
-- In_Generic_Scope --
----------------------
function In_Generic_Scope (E : Entity_Id) return Boolean is
S : Entity_Id;
begin
S := Scope (E);
while Present (S) and then S /= Standard_Standard loop
if Is_Generic_Unit (S) then
return True;
end if;
S := Scope (S);
end loop;
return False;
end In_Generic_Scope;
-- Start of processing for Analyze_Object_Renaming
begin
if Nam = Error then
return;
end if;
Check_SPARK_Restriction ("object renaming is not allowed", N);
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;
-- Complete analysis of the subtype mark in any case, for ASIS use
if Present (Subtype_Mark (N)) then
Find_Type (Subtype_Mark (N));
end if;
elsif Present (Subtype_Mark (N)) then
Find_Type (Subtype_Mark (N));
T := Entity (Subtype_Mark (N));
Analyze (Nam);
-- Reject renamings of conversions unless the type is tagged, or
-- the conversion is implicit (which can occur for cases of anonymous
-- access types in Ada 2012).
if Nkind (Nam) = N_Type_Conversion
and then Comes_From_Source (Nam)
and then not Is_Tagged_Type (T)
then
Error_Msg_N
("renaming of conversion only allowed for tagged types", Nam);
end if;
Resolve (Nam, T);
-- If the renamed object is a function call of a limited type,
-- the expansion of the renaming is complicated by the presence
-- of various temporaries and subtypes that capture constraints
-- of the renamed object. Rewrite node as an object declaration,
-- whose expansion is simpler. Given that the object is limited
-- there is no copy involved and no performance hit.
if Nkind (Nam) = N_Function_Call
and then Is_Immutably_Limited_Type (Etype (Nam))
and then not Is_Constrained (Etype (Nam))
and then Comes_From_Source (N)
then
Set_Etype (Id, T);
Set_Ekind (Id, E_Constant);
Rewrite (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Id,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
Expression => Relocate_Node (Nam)));
return;
end if;
-- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
-- when renaming declaration has a named access type. The Ada 2012
-- coverage rules allow an anonymous access type in the context of
-- an expected named general access type, but the renaming rules
-- require the types to be the same. (An exception is when the type
-- of the renaming is also an anonymous access type, which can only
-- happen due to a renaming created by the expander.)
if Nkind (Nam) = N_Type_Conversion
and then not Comes_From_Source (Nam)
and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
and then Ekind (T) /= E_Anonymous_Access_Type
then
Wrong_Type (Expression (Nam), T); -- Should we give better error???
end if;
-- Check that a class-wide object is not being renamed as an object
-- of a specific type. The test for access types is needed to exclude
-- cases where the renamed object is a dynamically tagged access
-- result, such as occurs in certain expansions.
if Is_Tagged_Type (T) then
Check_Dynamically_Tagged_Expression
(Expr => Nam,
Typ => T,
Related_Nod => N);
end if;
-- Ada 2005 (AI-230/AI-254): Access renaming
else pragma Assert (Present (Access_Definition (N)));
T := Access_Definition
(Related_Nod => N,
N => Access_Definition (N));
Analyze (Nam);
-- Ada 2005 AI05-105: if the declaration has an anonymous access
-- type, the renamed object must also have an anonymous type, and
-- this is a name resolution rule. This was implicit in the last part
-- of the first sentence in 8.5.1(3/2), and is made explicit by this
-- recent AI.
if not Is_Overloaded (Nam) then
if Ekind (Etype (Nam)) /= Ekind (T) then
Error_Msg_N
("expect anonymous access type in object renaming", N);
end if;
else
declare
I : Interp_Index;
It : Interp;
Typ : Entity_Id := Empty;
Seen : Boolean := False;
begin
Get_First_Interp (Nam, I, It);
while Present (It.Typ) loop
-- Renaming is ambiguous if more than one candidate
-- interpretation is type-conformant with the context.
if Ekind (It.Typ) = Ekind (T) then
if Ekind (T) = E_Anonymous_Access_Subprogram_Type
and then
Type_Conformant
(Designated_Type (T), Designated_Type (It.Typ))
then
if not Seen then
Seen := True;
else
Error_Msg_N
("ambiguous expression in renaming", Nam);
end if;
elsif Ekind (T) = E_Anonymous_Access_Type
and then
Covers (Designated_Type (T), Designated_Type (It.Typ))
then
if not Seen then
Seen := True;
else
Error_Msg_N
("ambiguous expression in renaming", Nam);
end if;
end if;
if Covers (T, It.Typ) then
Typ := It.Typ;
Set_Etype (Nam, Typ);
Set_Is_Overloaded (Nam, False);
end if;
end if;
Get_Next_Interp (I, It);
end loop;
end;
end if;
Resolve (Nam, T);
-- Ada 2005 (AI-231): "In the case where the type is defined by an
-- access_definition, the renamed entity shall be of an access-to-
-- constant type if and only if the access_definition defines an
-- access-to-constant type" ARM 8.5.1(4)
if Constant_Present (Access_Definition (N))
and then not Is_Access_Constant (Etype (Nam))
then
Error_Msg_N ("(Ada 2005): the renamed object is not "
& "access-to-constant (RM 8.5.1(6))", N);
elsif not Constant_Present (Access_Definition (N))
and then Is_Access_Constant (Etype (Nam))
then
Error_Msg_N ("(Ada 2005): the renamed object is not "
& "access-to-variable (RM 8.5.1(6))", N);
end if;
if Is_Access_Subprogram_Type (Etype (Nam)) then
Check_Subtype_Conformant
(Designated_Type (T), Designated_Type (Etype (Nam)));
elsif not Subtypes_Statically_Match
(Designated_Type (T),
Available_View (Designated_Type (Etype (Nam))))
then
Error_Msg_N
("subtype of renamed object does not statically match", N);
end if;
end if;
-- Special processing for renaming function return object. Some errors
-- and warnings are produced only for calls that come from source.
if Nkind (Nam) = N_Function_Call then
case Ada_Version is
-- Usage is illegal in Ada 83
when Ada_83 =>
if Comes_From_Source (Nam) then
Error_Msg_N
("(Ada 83) cannot rename function return object", Nam);
end if;
-- In Ada 95, warn for odd case of renaming parameterless function
-- call if this is not a limited type (where this is useful).
when others =>
if Warn_On_Object_Renames_Function
and then No (Parameter_Associations (Nam))
and then not Is_Limited_Type (Etype (Nam))
and then Comes_From_Source (Nam)
then
Error_Msg_N
("renaming function result object is suspicious?R?", Nam);
Error_Msg_NE
("\function & will be called only once?R?", Nam,
Entity (Name (Nam)));
Error_Msg_N -- CODEFIX
("\suggest using an initialized constant "
& "object instead?R?", Nam);
end if;
end case;
end if;
Check_Constrained_Object;
-- 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);
-- Ada 2005 (AI-326): Handle wrong use of incomplete type
if Nkind (Nam) = N_Explicit_Dereference
and then Ekind (Etype (T2)) = E_Incomplete_Type
then
Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
return;
elsif Ekind (Etype (T)) = E_Incomplete_Type then
Error_Msg_NE ("invalid use of incomplete type&", Id, T);
return;
end if;
-- Ada 2005 (AI-327)
if Ada_Version >= Ada_2005
and then Nkind (Nam) = N_Attribute_Reference
and then Attribute_Name (Nam) = Name_Priority
then
null;
elsif Ada_Version >= Ada_2005
and then Nkind (Nam) in N_Has_Entity
then
declare
Nam_Decl : Node_Id;
Nam_Ent : Entity_Id;
begin
if Nkind (Nam) = N_Attribute_Reference then
Nam_Ent := Entity (Prefix (Nam));
else
Nam_Ent := Entity (Nam);
end if;
Nam_Decl := Parent (Nam_Ent);
if Has_Null_Exclusion (N)
and then not Has_Null_Exclusion (Nam_Decl)
then
-- Ada 2005 (AI-423): If the object name denotes a generic
-- formal object of a generic unit G, and the object renaming
-- declaration occurs within the body of G or within the body
-- of a generic unit declared within the declarative region
-- of G, then the declaration of the formal object of G must
-- have a null exclusion or a null-excluding subtype.
if Is_Formal_Object (Nam_Ent)
and then In_Generic_Scope (Id)
then
if not Can_Never_Be_Null (Etype (Nam_Ent)) then
Error_Msg_N
("renamed formal does not exclude `NULL` "
& "(RM 8.5.1(4.6/2))", N);
elsif In_Package_Body (Scope (Id)) then
Error_Msg_N
("formal object does not have a null exclusion"
& "(RM 8.5.1(4.6/2))", N);
end if;
-- Ada 2005 (AI-423): Otherwise, the subtype of the object name
-- shall exclude null.
elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
Error_Msg_N
("renamed object does not exclude `NULL` "
& "(RM 8.5.1(4.6/2))", N);
-- An instance is illegal if it contains a renaming that
-- excludes null, and the actual does not. The renaming
-- declaration has already indicated that the declaration
-- of the renamed actual in the instance will raise
-- constraint_error.
elsif Nkind (Nam_Decl) = N_Object_Declaration
and then In_Instance
and then Present
(Corresponding_Generic_Association (Nam_Decl))
and then Nkind (Expression (Nam_Decl))
= N_Raise_Constraint_Error
then
Error_Msg_N
("renamed actual does not exclude `NULL` "
& "(RM 8.5.1(4.6/2))", N);
-- Finally, if there is a null exclusion, the subtype mark
-- must not be null-excluding.
elsif No (Access_Definition (N))
and then Can_Never_Be_Null (T)
then
Error_Msg_NE
("`NOT NULL` not allowed (& already excludes null)",
N, T);
end if;
elsif Can_Never_Be_Null (T)
and then not Can_Never_Be_Null (Etype (Nam_Ent))
then
Error_Msg_N
("renamed object does not exclude `NULL` "
& "(RM 8.5.1(4.6/2))", N);
elsif Has_Null_Exclusion (N)
and then No (Access_Definition (N))
and then Can_Never_Be_Null (T)
then
Error_Msg_NE
("`NOT NULL` not allowed (& already excludes null)", N, T);
end if;
end;
end if;
Set_Ekind (Id, E_Variable);
-- Initialize the object size and alignment. Note that we used to call
-- Init_Size_Align here, but that's wrong for objects which have only
-- an Esize, not an RM_Size field!
Init_Object_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);
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.
-- Illegal if the literal is the result of constant-folding an
-- attribute reference that is not a function.
or else (Is_Entity_Name (Nam)
and then Ekind (Entity (Nam)) = E_Enumeration_Literal
and then
Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
or else (Nkind (Nam) = N_Type_Conversion
and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
then
null;
elsif Nkind (Nam) = N_Type_Conversion then
Error_Msg_N
("renaming of conversion only allowed for tagged types", Nam);
-- Ada 2005 (AI-327)
elsif Ada_Version >= Ada_2005
and then Nkind (Nam) = N_Attribute_Reference
and then Attribute_Name (Nam) = Name_Priority
then
null;
-- Allow internally generated x'Reference expression
elsif Nkind (Nam) = N_Reference then
null;
else
Error_Msg_N ("expect object name in renaming", Nam);
end if;
Set_Etype (Id, T2);
if not Is_Variable (Nam) then
Set_Ekind (Id, E_Constant);
Set_Never_Set_In_Source (Id, True);
Set_Is_True_Constant (Id, True);
end if;
Set_Renamed_Object (Id, Nam);
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
end if;
-- Deal with dimensions
Analyze_Dimension (N);
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 a child 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);
-- Here for OK package renaming
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 the renaming is in the visible part of a package, then we set
-- Renamed_In_Spec for the renamed package, to prevent giving
-- warnings about no entities referenced. Such a warning would be
-- overenthusiastic, since clients can see entities in the renamed
-- package via the visible package renaming.
declare
Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
begin
if Ekind (Ent) = E_Package
and then not In_Private_Part (Ent)
and then In_Extended_Main_Source_Unit (N)
and then Ekind (Old_P) = E_Package
then
Set_Renamed_In_Spec (Old_P);
end if;
end;
-- 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;
begin
E := First_Entity (Old_P);
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;
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, New_P);
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;
Ind : 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);
end if;
return;
else
Typ := Any_Type;
Get_First_Interp (Nam, Ind, 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 (Ind, 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 : constant Node_Id := Name (N);
Sel : constant Node_Id := Selector_Name (Nam);
Is_Actual : constant Boolean := Present (Corresponding_Formal_Spec (N));
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);
else
-- Only mode conformance required for a renaming_as_declaration
Check_Mode_Conformant (New_S, Old_S, N);
end if;
Inherit_Renamed_Profile (New_S, Old_S);
-- The prefix can be an arbitrary expression that yields a task or
-- protected object, so it must be resolved.
Resolve (Prefix (Nam), Scope (Old_S));
end if;
Set_Convention (New_S, Convention (Old_S));
Set_Has_Completion (New_S, Inside_A_Generic);
-- AI05-0225: If the renamed entity is a procedure or entry of a
-- protected object, the target object must be a variable.
if Ekind (Scope (Old_S)) in Protected_Kind
and then Ekind (New_S) = E_Procedure
and then not Is_Variable (Prefix (Nam))
then
if Is_Actual then
Error_Msg_N
("target object of protected operation used as actual for "
& "formal procedure must be a variable", Nam);
else
Error_Msg_N
("target object of protected operation renamed as procedure, "
& "must be a variable", Nam);
end if;
end if;
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 : constant Node_Id := Name (N);
P : constant 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_Renamed_Primitive_Operation --
-----------------------------------------
procedure Analyze_Renamed_Primitive_Operation
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
Old_S : Entity_Id;
function Conforms
(Subp : Entity_Id;
Ctyp : Conformance_Type) return Boolean;
-- Verify that the signatures of the renamed entity and the new entity
-- match. The first formal of the renamed entity is skipped because it
-- is the target object in any subsequent call.
--------------
-- Conforms --
--------------
function Conforms
(Subp : Entity_Id;
Ctyp : Conformance_Type) return Boolean
is
Old_F : Entity_Id;
New_F : Entity_Id;
begin
if Ekind (Subp) /= Ekind (New_S) then
return False;
end if;
Old_F := Next_Formal (First_Formal (Subp));
New_F := First_Formal (New_S);
while Present (Old_F) and then Present (New_F) loop
if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
return False;
end if;
if Ctyp >= Mode_Conformant
and then Ekind (Old_F) /= Ekind (New_F)
then
return False;
end if;
Next_Formal (New_F);
Next_Formal (Old_F);
end loop;
return True;
end Conforms;
-- Start of processing for Analyze_Renamed_Primitive_Operation
begin
if not Is_Overloaded (Selector_Name (Name (N))) then
Old_S := Entity (Selector_Name (Name (N)));
if not Conforms (Old_S, Type_Conformant) then
Old_S := Any_Id;
end if;
else
-- Find the operation that matches the given signature
declare
It : Interp;
Ind : Interp_Index;
begin
Old_S := Any_Id;
Get_First_Interp (Selector_Name (Name (N)), Ind, It);
while Present (It.Nam) loop
if Conforms (It.Nam, Type_Conformant) then
Old_S := It.Nam;
end if;
Get_Next_Interp (Ind, It);
end loop;
end;
end if;
if Old_S = Any_Id then
Error_Msg_N (" no subprogram or entry matches specification", N);
else
if Is_Body then
if not Conforms (Old_S, Subtype_Conformant) then
Error_Msg_N ("subtype conformance error in renaming", N);
end if;
Generate_Reference (New_S, Defining_Entity (N), 'b');
Style.Check_Identifier (Defining_Entity (N), New_S);
else
-- Only mode conformance required for a renaming_as_declaration
if not Conforms (Old_S, Mode_Conformant) then
Error_Msg_N ("mode conformance error in renaming", N);
end if;
-- Enforce the rule given in (RM 6.3.1 (10.1/2)): a prefixed
-- view of a subprogram is intrinsic, because the compiler has
-- to generate a wrapper for any call to it. If the name in a
-- subprogram renaming is a prefixed view, the entity is thus
-- intrinsic, and 'Access cannot be applied to it.
Set_Convention (New_S, Convention_Intrinsic);
end if;
-- Inherit_Renamed_Profile (New_S, Old_S);
-- The prefix can be an arbitrary expression that yields an
-- object, so it must be resolved.
Resolve (Prefix (Name (N)));
end if;
end Analyze_Renamed_Primitive_Operation;
---------------------------------
-- Analyze_Subprogram_Renaming --
---------------------------------
procedure Analyze_Subprogram_Renaming (N : Node_Id) is
Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N);
Is_Actual : constant Boolean := Present (Formal_Spec);
Inst_Node : Node_Id := Empty;
Nam : constant Node_Id := Name (N);
New_S : Entity_Id;
Old_S : Entity_Id := Empty;
Rename_Spec : Entity_Id;
Save_AV : constant Ada_Version_Type := Ada_Version;
Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
Spec : constant Node_Id := Specification (N);
procedure Check_Null_Exclusion
(Ren : Entity_Id;
Sub : Entity_Id);
-- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
-- following AI rules:
--
-- If Ren is a renaming of a formal subprogram and one of its
-- parameters has a null exclusion, then the corresponding formal
-- in Sub must also have one. Otherwise the subtype of the Sub's
-- formal parameter must exclude null.
--
-- If Ren is a renaming of a formal function and its return
-- profile has a null exclusion, then Sub's return profile must
-- have one. Otherwise the subtype of Sub's return profile must
-- exclude null.
procedure Freeze_Actual_Profile;
-- In Ada 2012, enforce the freezing rule concerning formal incomplete
-- types: a callable entity freezes its profile, unless it has an
-- incomplete untagged formal (RM 13.14(10.2/3)).
function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
-- Find renamed entity when the declaration is a renaming_as_body and
-- the renamed entity may itself be a renaming_as_body. Used to enforce
-- rule that a renaming_as_body is illegal if the declaration occurs
-- before the subprogram it completes is frozen, and renaming indirectly
-- renames the subprogram itself.(Defect Report 8652/0027).
function Check_Class_Wide_Actual return Entity_Id;
-- AI05-0071: In an instance, if the actual for a formal type FT with
-- unknown discriminants is a class-wide type CT, and the generic has
-- a formal subprogram with a box for a primitive operation of FT,
-- then the corresponding actual subprogram denoted by the default is a
-- class-wide operation whose body is a dispatching call. We replace the
-- generated renaming declaration:
--
-- procedure P (X : CT) renames P;
--
-- by a different renaming and a class-wide operation:
--
-- procedure Pr (X : T) renames P; -- renames primitive operation
-- procedure P (X : CT); -- class-wide operation
-- ...
-- procedure P (X : CT) is begin Pr (X); end; -- dispatching call
--
-- This rule only applies if there is no explicit visible class-wide
-- operation at the point of the instantiation.
function Has_Class_Wide_Actual return Boolean;
-- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
-- defaulted formal subprogram when the actual for the controlling
-- formal type is class-wide.
-----------------------------
-- Check_Class_Wide_Actual --
-----------------------------
function Check_Class_Wide_Actual return Entity_Id is
Loc : constant Source_Ptr := Sloc (N);
F : Entity_Id;
Formal_Type : Entity_Id;
Actual_Type : Entity_Id;
New_Body : Node_Id;
New_Decl : Node_Id;
Result : Entity_Id;
function Make_Call (Prim_Op : Entity_Id) return Node_Id;
-- Build dispatching call for body of class-wide operation
function Make_Spec return Node_Id;
-- Create subprogram specification for declaration and body of
-- class-wide operation, using signature of renaming declaration.
---------------
-- Make_Call --
---------------
function Make_Call (Prim_Op : Entity_Id) return Node_Id is
Actuals : List_Id;
F : Node_Id;
begin
Actuals := New_List;
F := First (Parameter_Specifications (Specification (New_Decl)));
while Present (F) loop
Append_To (Actuals,
Make_Identifier (Loc, Chars (Defining_Identifier (F))));
Next (F);
end loop;
if Ekind_In (Prim_Op, E_Function, E_Operator) then
return Make_Simple_Return_Statement (Loc,
Expression =>
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Prim_Op, Loc),
Parameter_Associations => Actuals));
else
return
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (Prim_Op, Loc),
Parameter_Associations => Actuals);
end if;
end Make_Call;
---------------
-- Make_Spec --
---------------
function Make_Spec return Node_Id is
Param_Specs : constant List_Id := Copy_Parameter_List (New_S);
begin
if Ekind (New_S) = E_Procedure then
return
Make_Procedure_Specification (Loc,
Defining_Unit_Name =>
Make_Defining_Identifier (Loc,
Chars (Defining_Unit_Name (Spec))),
Parameter_Specifications => Param_Specs);
else
return
Make_Function_Specification (Loc,
Defining_Unit_Name =>
Make_Defining_Identifier (Loc,
Chars (Defining_Unit_Name (Spec))),
Parameter_Specifications => Param_Specs,
Result_Definition =>
New_Copy_Tree (Result_Definition (Spec)));
end if;
end Make_Spec;
-- Start of processing for Check_Class_Wide_Actual
begin
Result := Any_Id;
Formal_Type := Empty;
Actual_Type := Empty;
F := First_Formal (Formal_Spec);
while Present (F) loop
if Has_Unknown_Discriminants (Etype (F))
and then not Is_Class_Wide_Type (Etype (F))
and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F)))
then
Formal_Type := Etype (F);
Actual_Type := Etype (Get_Instance_Of (Formal_Type));
exit;
end if;
Next_Formal (F);
end loop;
if Present (Formal_Type) then
-- Create declaration and body for class-wide operation
New_Decl :=
Make_Subprogram_Declaration (Loc, Specification => Make_Spec);
New_Body :=
Make_Subprogram_Body (Loc,
Specification => Make_Spec,
Declarations => No_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, New_List));
-- Modify Spec and create internal name for renaming of primitive
-- operation.
Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R'));
F := First (Parameter_Specifications (Spec));
while Present (F) loop
if Nkind (Parameter_Type (F)) = N_Identifier
and then Is_Class_Wide_Type (Entity (Parameter_Type (F)))
then
Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc));
end if;
Next (F);
end loop;
New_S := Analyze_Subprogram_Specification (Spec);
Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
end if;
if Result /= Any_Id then
Insert_Before (N, New_Decl);
Analyze (New_Decl);
-- Add dispatching call to body of class-wide operation
Append (Make_Call (Result),
Statements (Handled_Statement_Sequence (New_Body)));
-- The generated body does not freeze. It is analyzed when the
-- generated operation is frozen. This body is only needed if
-- expansion is enabled.
if Expander_Active then
Append_Freeze_Action (Defining_Entity (New_Decl), New_Body);
end if;
Result := Defining_Entity (New_Decl);
end if;
-- Return the class-wide operation if one was created
return Result;
end Check_Class_Wide_Actual;
--------------------------
-- Check_Null_Exclusion --
--------------------------
procedure Check_Null_Exclusion
(Ren : Entity_Id;
Sub : Entity_Id)
is
Ren_Formal : Entity_Id;
Sub_Formal : Entity_Id;
begin
-- Parameter check
Ren_Formal := First_Formal (Ren);
Sub_Formal := First_Formal (Sub);
while Present (Ren_Formal)
and then Present (Sub_Formal)
loop
if Has_Null_Exclusion (Parent (Ren_Formal))
and then
not (Has_Null_Exclusion (Parent (Sub_Formal))
or else Can_Never_Be_Null (Etype (Sub_Formal)))
then
Error_Msg_NE
("`NOT NULL` required for parameter &",
Parent (Sub_Formal), Sub_Formal);
end if;
Next_Formal (Ren_Formal);
Next_Formal (Sub_Formal);
end loop;
-- Return profile check
if Nkind (Parent (Ren)) = N_Function_Specification
and then Nkind (Parent (Sub)) = N_Function_Specification
and then Has_Null_Exclusion (Parent (Ren))
and then
not (Has_Null_Exclusion (Parent (Sub))
or else Can_Never_Be_Null (Etype (Sub)))
then
Error_Msg_N
("return must specify `NOT NULL`",
Result_Definition (Parent (Sub)));
end if;
end Check_Null_Exclusion;
---------------------------
-- Freeze_Actual_Profile --
---------------------------
procedure Freeze_Actual_Profile is
F : Entity_Id;
Has_Untagged_Inc : Boolean;
Instantiation_Node : constant Node_Id := Parent (N);
begin
if Ada_Version >= Ada_2012 then
F := First_Formal (Formal_Spec);
Has_Untagged_Inc := False;
while Present (F) loop
if Ekind (Etype (F)) = E_Incomplete_Type
and then not Is_Tagged_Type (Etype (F))
then
Has_Untagged_Inc := True;
exit;
end if;
F := Next_Formal (F);
end loop;
if Ekind (Formal_Spec) = E_Function
and then Ekind (Etype (Formal_Spec)) = E_Incomplete_Type
and then not Is_Tagged_Type (Etype (F))
then
Has_Untagged_Inc := True;
end if;
if not Has_Untagged_Inc then
F := First_Formal (Old_S);
while Present (F) loop
Freeze_Before (Instantiation_Node, Etype (F));
if Is_Incomplete_Or_Private_Type (Etype (F))
and then No (Underlying_Type (Etype (F)))
and then not Is_Generic_Type (Etype (F))
then
Error_Msg_NE
("type& must be frozen before this point",
Instantiation_Node, Etype (F));
end if;
F := Next_Formal (F);
end loop;
end if;
end if;
end Freeze_Actual_Profile;
---------------------------
-- Has_Class_Wide_Actual --
---------------------------
function Has_Class_Wide_Actual return Boolean is
F_Nam : Entity_Id;
F_Spec : Entity_Id;
begin
if Is_Actual
and then Nkind (Nam) in N_Has_Entity
and then Present (Entity (Nam))
and then Is_Dispatching_Operation (Entity (Nam))
then
F_Nam := First_Entity (Entity (Nam));
F_Spec := First_Formal (Formal_Spec);
while Present (F_Nam)
and then Present (F_Spec)
loop
if Is_Controlling_Formal (F_Nam)
and then Has_Unknown_Discriminants (Etype (F_Spec))
and then not Is_Class_Wide_Type (Etype (F_Spec))
and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F_Spec)))
then
return True;
end if;
Next_Entity (F_Nam);
Next_Formal (F_Spec);
end loop;
end if;
return False;
end Has_Class_Wide_Actual;
-------------------------
-- Original_Subprogram --
-------------------------
function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
Orig_Decl : Node_Id;
Orig_Subp : Entity_Id;
begin
-- First case: renamed entity is itself a renaming
if Present (Alias (Subp)) then
return Alias (Subp);
elsif
Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
and then Present
(Corresponding_Body (Unit_Declaration_Node (Subp)))
then
-- Check if renamed entity is a renaming_as_body
Orig_Decl :=
Unit_Declaration_Node
(Corresponding_Body (Unit_Declaration_Node (Subp)));
if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
Orig_Subp := Entity (Name (Orig_Decl));
if Orig_Subp = Rename_Spec then
-- Circularity detected
return Orig_Subp;
else
return (Original_Subprogram (Orig_Subp));
end if;
else
return Subp;
end if;
else
return Subp;
end if;
end Original_Subprogram;
CW_Actual : constant Boolean := Has_Class_Wide_Actual;
-- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
-- defaulted formal subprogram when the actual for a related formal
-- type is class-wide.
-- Start of processing for Analyze_Subprogram_Renaming
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
-- In the case of an abstract formal subprogram association, rewrite
-- an actual given by a stream attribute as the name of the
-- corresponding stream primitive of the type.
-- In a generic context the stream operations are not generated, and
-- this must be treated as a normal attribute reference, to be
-- expanded in subsequent instantiations.
if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec)
and then Full_Expander_Active
then
declare
Stream_Prim : Entity_Id;
Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
begin
-- The class-wide forms of the stream attributes are not
-- primitive dispatching operations (even though they
-- internally dispatch to a stream attribute).
if Is_Class_Wide_Type (Prefix_Type) then
Error_Msg_N
("attribute must be a primitive dispatching operation",
Nam);
return;
end if;
-- Retrieve the primitive subprogram associated with the
-- attribute. This can only be a stream attribute, since those
-- are the only ones that are dispatching (and the actual for
-- an abstract formal subprogram must be dispatching
-- operation).
begin
case Attribute_Name (Nam) is
when Name_Input =>
Stream_Prim :=
Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
when Name_Output =>
Stream_Prim :=
Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
when Name_Read =>
Stream_Prim :=
Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
when Name_Write =>
Stream_Prim :=
Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
when others =>
Error_Msg_N
("attribute must be a primitive"
& " dispatching operation", Nam);
return;
end case;
exception
-- If no operation was found, and the type is limited,
-- the user should have defined one.
when Program_Error =>
if Is_Limited_Type (Prefix_Type) then
Error_Msg_NE
("stream operation not defined for type&",
N, Prefix_Type);
return;
-- Otherwise, compiler should have generated default
else
raise;
end if;
end;
-- Rewrite the attribute into the name of its corresponding
-- primitive dispatching subprogram. We can then proceed with
-- the usual processing for subprogram renamings.
declare
Prim_Name : constant Node_Id :=
Make_Identifier (Sloc (Nam),
Chars => Chars (Stream_Prim));
begin
Set_Entity (Prim_Name, Stream_Prim);
Rewrite (Nam, Prim_Name);
Analyze (Nam);
end;
end;
-- Normal processing for a renaming of an attribute
else
Attribute_Renaming (N);
return;
end if;
end if;
-- Check whether this declaration corresponds to the instantiation
-- of a formal subprogram.
-- 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 Is_Actual then
Inst_Node := Unit_Declaration_Node (Formal_Spec);
-- Check whether the renaming is for a defaulted actual subprogram
-- with a class-wide actual.
if CW_Actual then
New_S := Analyze_Subprogram_Specification (Spec);
Old_S := Check_Class_Wide_Actual;
elsif 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_Subprogram_Specification (Spec);
-- Operator case
if Ekind (Entity (Nam)) = E_Operator then
-- Box present
if Box_Present (Inst_Node) then
Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
-- If there is an immediately visible homonym of the operator
-- and the declaration has a default, this is worth a warning
-- because the user probably did not intend to get the pre-
-- defined operator, visible in the generic declaration. To
-- find if there is an intended candidate, analyze the renaming
-- again in the current context.
elsif Scope (Old_S) = Standard_Standard
and then Present (Default_Name (Inst_Node))
then
declare
Decl : constant Node_Id := New_Copy_Tree (N);
Hidden : Entity_Id;
begin
Set_Entity (Name (Decl), Empty);
Analyze (Name (Decl));
Hidden :=
Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
if Present (Hidden)
and then In_Open_Scopes (Scope (Hidden))
and then Is_Immediately_Visible (Hidden)
and then Comes_From_Source (Hidden)
and then Hidden /= Old_S
then
Error_Msg_Sloc := Sloc (Hidden);
Error_Msg_N ("default subprogram is resolved " &
"in the generic declaration " &
"(RM 12.6(17))??", N);
Error_Msg_NE ("\and will not use & #??", N, Hidden);
end if;
end;
end if;
end if;
else
Analyze (Nam);
New_S := Analyze_Subprogram_Specification (Spec);
end if;
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_Subprogram_Specification (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);
-- Case of Renaming_As_Body
if Present (Rename_Spec) then
-- Renaming declaration is the completion of the declaration of
-- Rename_Spec. We build an actual body for it at the freezing point.
Set_Corresponding_Spec (N, Rename_Spec);
-- Deal with special case of stream functions of abstract types
-- and interfaces.
if Nkind (Unit_Declaration_Node (Rename_Spec)) =
N_Abstract_Subprogram_Declaration
then
-- Input stream functions are abstract if the object type is
-- abstract. Similarly, all default stream functions for an
-- interface type are abstract. However, these subprograms may
-- receive explicit declarations in representation clauses, making
-- the attribute subprograms usable as defaults in subsequent
-- type extensions.
-- In this case we rewrite the declaration to make the subprogram
-- non-abstract. We remove the previous declaration, and insert
-- the new one at the point of the renaming, to prevent premature
-- access to unfrozen types. The new declaration reuses the
-- specification of the previous one, and must not be analyzed.
pragma Assert
(Is_Primitive (Entity (Nam))
and then
Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
declare
Old_Decl : constant Node_Id :=
Unit_Declaration_Node (Rename_Spec);
New_Decl : constant Node_Id :=
Make_Subprogram_Declaration (Sloc (N),
Specification =>
Relocate_Node (Specification (Old_Decl)));
begin
Remove (Old_Decl);
Insert_After (N, New_Decl);
Set_Is_Abstract_Subprogram (Rename_Spec, False);
Set_Analyzed (New_Decl);
end;
end if;
Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
if Ada_Version = 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);
-- The specification does not introduce new formals, but only
-- repeats the formals of the original subprogram declaration.
-- For cross-reference purposes, and for refactoring tools, we
-- treat the formals of the renaming declaration as body formals.
Reference_Body_Formals (Rename_Spec, New_S);
-- Indicate that the entity in the declaration functions like the
-- corresponding body, and is not a new entity. The body will be
-- constructed later at the freeze point, so indicate that the
-- completion has not been seen yet.
Set_Ekind (New_S, E_Subprogram_Body);
New_S := Rename_Spec;
Set_Has_Completion (Rename_Spec, False);
-- Ada 2005: check overriding indicator
if Present (Overridden_Operation (Rename_Spec)) then
if Must_Not_Override (Specification (N)) then
Error_Msg_NE
("subprogram& overrides inherited operation",
N, Rename_Spec);
elsif
Style_Check and then not Must_Override (Specification (N))
then
Style.Missing_Overriding (N, Rename_Spec);
end if;
elsif Must_Override (Specification (N)) then
Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
end if;
-- Normal subprogram renaming (not renaming as body)
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.
-- Elaboration checks refer to the real entity, not the one created by
-- the renaming declaration.
Set_Kill_Elaboration_Checks (New_S, True);
if Etype (Nam) = Any_Type then
Set_Has_Completion (New_S);
return;
elsif Nkind (Nam) = N_Selected_Component then
-- A prefix of the form A.B can designate an entry of task A, a
-- protected operation of protected object A, or finally a primitive
-- operation of object A. In the later case, A is an object of some
-- tagged type, or an access type that denotes one such. To further
-- distinguish these cases, note that the scope of a task entry or
-- protected operation is type of the prefix.
-- The prefix could be an overloaded function call that returns both
-- kinds of operations. This overloading pathology is left to the
-- dedicated reader ???
declare
T : constant Entity_Id := Etype (Prefix (Nam));
begin
if Present (T)
and then
(Is_Tagged_Type (T)
or else
(Is_Access_Type (T)
and then
Is_Tagged_Type (Designated_Type (T))))
and then Scope (Entity (Selector_Name (Nam))) /= T
then
Analyze_Renamed_Primitive_Operation
(N, New_S, Present (Rename_Spec));
return;
else
-- Renamed entity is an entry or protected operation. For those
-- cases an explicit body is built (at the point of freezing of
-- this entity) that contains a call to the renamed entity.
-- This is not allowed for renaming as body if the renamed
-- spec is already frozen (see RM 8.5.4(5) for details).
if Present (Rename_Spec)
and then Is_Frozen (Rename_Spec)
then
Error_Msg_N
("renaming-as-body cannot rename entry as subprogram", N);
Error_Msg_NE
("\since & is already frozen (RM 8.5.4(5))",
N, Rename_Spec);
else
Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
end if;
return;
end if;
end;
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)
or else not Is_Overloadable (Entity (Nam))
then
-- Do not mention the renaming if it comes from an instance
if not Is_Actual then
Error_Msg_N ("expect valid subprogram name in renaming", N);
else
Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
end if;
return;
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.
-- This is a bit of a kludge, which introduces a really irregular use of
-- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this
-- ???
Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
Ada_Version_Explicit := Ada_Version;
if No (Old_S) then
Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
-- The visible operation may be an inherited abstract operation that
-- was overridden in the private part, in which case a call will
-- dispatch to the overriding operation. Use the overriding one in
-- the renaming declaration, to prevent spurious errors below.
if Is_Overloadable (Old_S)
and then Is_Abstract_Subprogram (Old_S)
and then No (DTC_Entity (Old_S))
and then Present (Alias (Old_S))
and then not Is_Abstract_Subprogram (Alias (Old_S))
and then Present (Overridden_Operation (Alias (Old_S)))
then
Old_S := Alias (Old_S);
end if;
-- When the renamed subprogram is overloaded and used as an actual
-- of a generic, its entity is set to the first available homonym.
-- We must first disambiguate the name, then set the proper entity.
if Is_Actual and then Is_Overloaded (Nam) then
Set_Entity (Nam, Old_S);
end if;
end if;
-- Most common case: subprogram renames subprogram. No body is generated
-- in this case, so we must indicate the declaration is complete as is.
-- and inherit various attributes of the renamed subprogram.
if No (Rename_Spec) then
Set_Has_Completion (New_S);
Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
-- Ada 2005 (AI-423): Check the consistency of null exclusions
-- between a subprogram and its correct renaming.
-- Note: the Any_Id check is a guard that prevents compiler crashes
-- when performing a null exclusion check between a renaming and a
-- renamed subprogram that has been found to be illegal.
if Ada_Version >= Ada_2005
and then Entity (Nam) /= Any_Id
then
Check_Null_Exclusion
(Ren => New_S,
Sub => Entity (Nam));
end if;
-- Enforce the Ada 2005 rule that the renamed entity cannot require
-- overriding. The flag Requires_Overriding is set very selectively
-- and misses some other illegal cases. The additional conditions
-- checked below are sufficient but not necessary ???
-- The rule does not apply to the renaming generated for an actual
-- subprogram in an instance.
if Is_Actual then
null;
-- Guard against previous errors, and omit renamings of predefined
-- operators.
elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
null;
elsif Requires_Overriding (Old_S)
or else
(Is_Abstract_Subprogram (Old_S)
and then Present (Find_Dispatching_Type (Old_S))
and then
not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
then
Error_Msg_N
("renamed entity cannot be "
& "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
end if;
end if;
if Old_S /= Any_Id then
if Is_Actual and then From_Default (N) 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;
Check_Internal_Protected_Use (N, Old_S);
-- 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) then
if not Has_Convention_Pragma (Rename_Spec) then
Set_Convention (New_S, Convention (Old_S));
end if;
if Ekind (Old_S) /= E_Operator then
Check_Mode_Conformant (New_S, Old_S, Spec);
end if;
if Original_Subprogram (Old_S) = Rename_Spec then
Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
end if;
else
Check_Subtype_Conformant (New_S, Old_S, Spec);
end if;
Check_Frozen_Renaming (N, Rename_Spec);
-- Check explicitly that renamed entity is not intrinsic, because
-- in a generic the renamed body is not built. In this case,
-- the renaming_as_body is a completion.
if Inside_A_Generic then
if Is_Frozen (Rename_Spec)
and then Is_Intrinsic_Subprogram (Old_S)
then
Error_Msg_N
("subprogram in renaming_as_body cannot be intrinsic",
Name (N));
end if;
Set_Has_Completion (Rename_Spec);
end if;
elsif Ekind (Old_S) /= E_Operator then
-- If this a defaulted subprogram for a class-wide actual there is
-- no check for mode conformance, given that the signatures don't
-- match (the source mentions T but the actual mentions T'Class).
if CW_Actual then
null;
else
Check_Mode_Conformant (New_S, Old_S);
end if;
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_Intrinsic_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).
-- Also, if this is a renaming of inequality, the renamed operator
-- is intrinsic, but what matters is the corresponding equality
-- operator, which may be user-defined.
Set_Is_Intrinsic_Subprogram
(New_S,
Is_Intrinsic_Subprogram (Old_S)
and then
(Chars (Old_S) /= Name_Op_Ne
or else Ekind (Old_S) = E_Operator
or else
Is_Intrinsic_Subprogram
(Corresponding_Equality (Old_S))));
if Ekind (Alias (New_S)) = E_Operator then
Set_Has_Delayed_Freeze (New_S, False);
end if;
-- If the renaming corresponds to an association for an abstract
-- formal subprogram, then various attributes must be set to
-- indicate that the renaming is an abstract dispatching operation
-- with a controlling type.
if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
-- Mark the renaming as abstract here, so Find_Dispatching_Type
-- see it as corresponding to a generic association for a
-- formal abstract subprogram
Set_Is_Abstract_Subprogram (New_S);
declare
New_S_Ctrl_Type : constant Entity_Id :=
Find_Dispatching_Type (New_S);
Old_S_Ctrl_Type : constant Entity_Id :=
Find_Dispatching_Type (Old_S);
begin
if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
Error_Msg_NE
("actual must be dispatching subprogram for type&",
Nam, New_S_Ctrl_Type);
else
Set_Is_Dispatching_Operation (New_S);
Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
-- If the actual in the formal subprogram is itself a
-- formal abstract subprogram association, there's no
-- dispatch table component or position to inherit.
if Present (DTC_Entity (Old_S)) then
Set_DTC_Entity (New_S, DTC_Entity (Old_S));
Set_DT_Position (New_S, DT_Position (Old_S));
end if;
end if;
end;
end if;
end if;
if Is_Actual then
null;
-- The following is illegal, because F hides whatever other F may
-- be around:
-- function F (..) renames F;
elsif 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);
elsif Nkind (Nam) = N_Expanded_Name
and then Entity (Prefix (Nam)) = Current_Scope
and then Chars (Selector_Name (Nam)) = Chars (New_S)
then
if Overriding_Renamings then
null;
else
Error_Msg_NE
("implicit operation& is not visible (RM 8.3 (15))",
Nam, Old_S);
end if;
end if;
Set_Convention (New_S, Convention (Old_S));
if Is_Abstract_Subprogram (Old_S) then
if Present (Rename_Spec) then
Error_Msg_N
("a renaming-as-body cannot rename an abstract subprogram",
N);
Set_Has_Completion (Rename_Spec);
else
Set_Is_Abstract_Subprogram (New_S);
end if;
end if;
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);
Freeze_Actual_Profile;
Set_Has_Delayed_Freeze (New_S, False);
Freeze_Before (N, New_S);
-- An abstract subprogram is only allowed as an actual in the case
-- where the formal subprogram is also abstract.
if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
and then Is_Abstract_Subprogram (Old_S)
and then not Is_Abstract_Subprogram (Formal_Spec)
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;
T1 : Entity_Id;
begin
F1 := First_Formal (Candidate_Renaming);
F2 := First_Formal (New_S);
T1 := First_Subtype (Etype (F1));
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;
if Nkind (Nam) = N_Operator_Symbol
and then From_Default (N)
then
Error_Msg_Node_2 := T1;
Error_Msg_NE
("default & on & is not directly visible",
Nam, Nam);
end if;
end;
end if;
end if;
-- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
-- controlling access parameters are known non-null for the renamed
-- subprogram. Test also applies to a subprogram instantiation that
-- is dispatching. Test is skipped if some previous error was detected
-- that set Old_S to Any_Id.
if Ada_Version >= Ada_2005
and then Old_S /= Any_Id
and then not Is_Dispatching_Operation (Old_S)
and then Is_Dispatching_Operation (New_S)
then
declare
Old_F : Entity_Id;
New_F : Entity_Id;
begin
Old_F := First_Formal (Old_S);
New_F := First_Formal (New_S);
while Present (Old_F) loop
if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
and then Is_Controlling_Formal (New_F)
and then not Can_Never_Be_Null (Old_F)
then
Error_Msg_N ("access parameter is controlling,", New_F);
Error_Msg_NE
("\corresponding parameter of& "
& "must be explicitly null excluding", New_F, Old_S);
end if;
Next_Formal (Old_F);
Next_Formal (New_F);
end loop;
end;
end if;
-- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
-- is to warn if an operator is being renamed as a different operator.
-- If the operator is predefined, examine the kind of the entity, not
-- the abbreviated declaration in Standard.
if Comes_From_Source (N)
and then Present (Old_S)
and then
(Nkind (Old_S) = N_Defining_Operator_Symbol
or else Ekind (Old_S) = E_Operator)
and then Nkind (New_S) = N_Defining_Operator_Symbol
and then Chars (Old_S) /= Chars (New_S)
then
Error_Msg_NE
("& is being renamed as a different operator??", N, Old_S);
end if;
-- Check for renaming of obsolescent subprogram
Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
-- Another warning or some utility: if the new subprogram as the same
-- name as the old one, the old one is not hidden by an outer homograph,
-- the new one is not a public symbol, and the old one is otherwise
-- directly visible, the renaming is superfluous.
if Chars (Old_S) = Chars (New_S)
and then Comes_From_Source (N)
and then Scope (Old_S) /= Standard_Standard
and then Warn_On_Redundant_Constructs
and then
(Is_Immediately_Visible (Old_S)
or else Is_Potentially_Use_Visible (Old_S))
and then Is_Overloadable (Current_Scope)
and then Chars (Current_Scope) /= Chars (Old_S)
then
Error_Msg_N
("redundant renaming, entity is directly visible?r?", Name (N));
end if;
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, New_S);
end if;
Ada_Version := Save_AV;
Ada_Version_Explicit := Save_AV_Exp;
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;
-- Start of processing for Analyze_Use_Package
begin
Check_SPARK_Restriction ("use clause is not allowed", N);
Set_Hidden_By_Use_Clause (N, No_Elist);
-- Use clause 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, which 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;
begin
Pref := Prefix (Pack_Name);
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 -- CODEFIX
("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;
else
if Nkind (Parent (N)) = N_Compilation_Unit then
Check_In_Previous_With_Clause (N, Pack_Name);
end if;
if Applicable_Use (Pack_Name) then
Use_One_Package (Pack, N);
end if;
end if;
-- Report error because name denotes something other than a package
else
Error_Msg_N ("& is not a package", Pack_Name);
end if;
Next (Pack_Name);
end loop;
end Analyze_Use_Package;
----------------------
-- Analyze_Use_Type --
----------------------
procedure Analyze_Use_Type (N : Node_Id) is
E : Entity_Id;
Id : Node_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;
-- If the Used_Operations list is already initialized, the clause has
-- been analyzed previously, and it is begin reinstalled, for example
-- when the clause appears in a package spec and we are compiling the
-- corresponding package body. In that case, make the entities on the
-- existing list use_visible, and mark the corresponding types In_Use.
if Present (Used_Operations (N)) then
declare
Mark : Node_Id;
Elmt : Elmt_Id;
begin
Mark := First (Subtype_Marks (N));
while Present (Mark) loop
Use_One_Type (Mark, Installed => True);
Next (Mark);
end loop;
Elmt := First_Elmt (Used_Operations (N));
while Present (Elmt) loop
Set_Is_Potentially_Use_Visible (Node (Elmt));
Next_Elmt (Elmt);
end loop;
end;
return;
end if;
-- Otherwise, create new list and attach to it the operations that
-- are made use-visible by the clause.
Set_Used_Operations (N, New_Elmt_List);
Id := First (Subtype_Marks (N));
while Present (Id) loop
Find_Type (Id);
E := Entity (Id);
if E /= Any_Type then
Use_One_Type (Id);
if Nkind (Parent (N)) = N_Compilation_Unit then
if Nkind (Id) = N_Identifier then
Error_Msg_N ("type is not directly visible", Id);
elsif Is_Child_Unit (Scope (E))
and then Scope (E) /= System_Aux_Id
then
Check_In_Previous_With_Clause (N, Prefix (Id));
end if;
end if;
else
-- If the use_type_clause appears in a compilation unit context,
-- check whether it comes from a unit that may appear in a
-- limited_with_clause, for a better error message.
if Nkind (Parent (N)) = N_Compilation_Unit
and then Nkind (Id) /= N_Identifier
then
declare
Item : Node_Id;
Pref : Node_Id;
function Mentioned (Nam : Node_Id) return Boolean;
-- Check whether the prefix of expanded name for the type
-- appears in the prefix of some limited_with_clause.
---------------
-- Mentioned --
---------------
function Mentioned (Nam : Node_Id) return Boolean is
begin
return Nkind (Name (Item)) = N_Selected_Component
and then
Chars (Prefix (Name (Item))) = Chars (Nam);
end Mentioned;
begin
Pref := Prefix (Id);
Item := First (Context_Items (Parent (N)));
while Present (Item) and then Item /= N loop
if Nkind (Item) = N_With_Clause
and then Limited_Present (Item)
and then Mentioned (Pref)
then
Change_Error_Text
(Get_Msg_Id, "premature usage of incomplete type");
end if;
Next (Item);
end loop;
end;
end if;
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
if Warn_On_Redundant_Constructs
and then Pack = Current_Scope
then
Error_Msg_NE -- CODEFIX
("& is already use-visible within itself?r?", Pack_Name, Pack);
end if;
return False;
elsif In_Use (Pack) then
Note_Redundant_Use (Pack_Name);
return False;
elsif Present (Renamed_Object (Pack))
and then In_Use (Renamed_Object (Pack))
then
Note_Redundant_Use (Pack_Name);
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))));
-- The expressions in the attribute reference are not freeze
-- points. Neither is the attribute as a whole, see below.
Set_Must_Not_Freeze (Last (Expr_List));
Next (Param_Spec);
end loop;
end if;
-- Immediate error if too many formals. Other mismatches in number or
-- 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);
-- Error if the attribute reference has expressions that look like
-- formal parameters.
elsif Present (Expressions (Nam)) then
Error_Msg_N ("illegal expressions in attribute reference", Nam);
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_Formal_Spec (N))
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 : constant Entity_Id := Make_Temporary (Loc, 'R', Nam);
Decl : Node_Id;
begin
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 (Result_Definition (Spec));
Rewrite (Result_Definition (Spec),
New_Reference_To (
Base_Type (Entity (Result_Definition (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_Simple_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;
-- In case of tagged types we add the body of the generated function to
-- the freezing actions of the type (because in the general case such
-- type is still not frozen). We exclude from this processing generic
-- formal subprograms found in instantiations and AST_Entry renamings.
-- We must exclude VM targets and restricted run-time libraries because
-- entity AST_Handler is defined in package System.Aux_Dec which is not
-- available in those platforms. Note that we cannot use the function
-- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
-- the ZFP run-time library is not defined as a profile, and we do not
-- want to deal with AST_Handler in ZFP mode.
if VM_Target = No_VM
and then not Configurable_Run_Time_Mode
and then not Present (Corresponding_Formal_Spec (N))
and then Etype (Nam) /= RTE (RE_AST_Handler)
then
declare
P : constant Entity_Id := Prefix (Nam);
begin
Find_Type (P);
if Is_Tagged_Type (Etype (P)) then
Ensure_Freeze_Node (Etype (P));
Append_Freeze_Action (Etype (P), Body_Node);
else
Rewrite (N, Body_Node);
Analyze (N);
Set_Etype (New_S, Base_Type (Etype (New_S)));
end if;
end;
-- Generic formal subprograms or AST_Handler renaming
else
Rewrite (N, Body_Node);
Analyze (N);
Set_Etype (New_S, Base_Type (Etype (New_S)));
end if;
if Is_Compilation_Unit (New_S) then
Error_Msg_N
("a library unit can only rename another library unit", N);
end if;
-- 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
Pack : Entity_Id;
Level : Int := Scope_Stack.Last;
begin
if not Is_Compilation_Unit (Current_Scope)
or else not Is_Child_Unit (Current_Scope)
then
null; -- Common case
elsif Defining_Entity (Parent (N)) = Current_Scope then
null; -- Common case for compilation unit
else
-- If declaration appears in some other scope, it must be in some
-- parent unit when compiling a child.
Pack := Defining_Entity (Parent (N));
if not In_Open_Scopes (Pack) then
null; -- default as well
else
-- Find entry for parent unit in scope stack
while Scope_Stack.Table (Level).Entity /= Pack loop
Level := Level - 1;
end loop;
end if;
end if;
Set_Next_Use_Clause (N,
Scope_Stack.Table (Level).First_Use_Clause);
Scope_Stack.Table (Level).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)
and then Operating_Mode /= Check_Semantics
then
Append_Freeze_Action (Old_S, B_Node);
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;
-------------------------------
-- Set_Entity_Or_Discriminal --
-------------------------------
procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
P : Node_Id;
begin
-- If the entity is not a discriminant, or else expansion is disabled,
-- simply set the entity.
if not In_Spec_Expression
or else Ekind (E) /= E_Discriminant
or else Inside_A_Generic
then
Set_Entity_With_Style_Check (N, E);
-- The replacement of a discriminant by the corresponding discriminal
-- is not done for a task discriminant that appears in a default
-- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
-- for details on their handling.
elsif Is_Concurrent_Type (Scope (E)) then
P := Parent (N);
while Present (P)
and then not Nkind_In (P, N_Parameter_Specification,
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;
-- Otherwise, this is a discriminant in a context in which
-- it is a reference to the corresponding parameter of the
-- init proc for the enclosing type.
else
Set_Entity (N, Discriminal (E));
end if;
end Set_Entity_Or_Discriminal;
-----------------------------------
-- Check_In_Previous_With_Clause --
-----------------------------------
procedure Check_In_Previous_With_Clause
(N : Node_Id;
Nam : Entity_Id)
is
Pack : constant Entity_Id := Entity (Original_Node (Nam));
Item : Node_Id;
Par : Node_Id;
begin
Item := First (Context_Items (Parent (N)));
while Present (Item)
and then Item /= N
loop
if Nkind (Item) = N_With_Clause
-- Protect the frontend against previous critical errors
and then Nkind (Name (Item)) /= N_Selected_Component
and then Entity (Name (Item)) = Pack
then
Par := Nam;
-- Find root library unit in with_clause
while Nkind (Par) = N_Expanded_Name loop
Par := Prefix (Par);
end loop;
if Is_Child_Unit (Entity (Original_Node (Par))) then
Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
else
return;
end if;
end if;
Next (Item);
end loop;
-- On exit, package is not mentioned in a previous with_clause.
-- Check if its prefix is.
if Nkind (Nam) = N_Expanded_Name then
Check_In_Previous_With_Clause (N, Prefix (Nam));
elsif Pack /= Any_Id then
Error_Msg_NE ("& is not visible", Nam, Pack);
end if;
end Check_In_Previous_With_Clause;
---------------------------------
-- 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;
-- Check for library unit. Note that we used to check for the scope
-- being Standard here, but that was wrong for Standard itself.
elsif not Is_Compilation_Unit (Old_E)
and then not Is_Child_Unit (Old_E)
then
Error_Msg_N ("renamed unit must be a library unit", Name (N));
-- Entities defined in Standard (operators and boolean literals) cannot
-- be renamed as library units.
elsif Scope (Old_E) = Standard_Standard
and then Sloc (Old_E) = Standard_Location
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 Is_Package_Or_Generic_Package (Old_E) 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;
Set_Is_Immediately_Visible (Id, False);
Outer := Homonym (Id);
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_In (Parent (Decl), N_Protected_Definition,
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;
begin
-- Remove Use_Type clauses first, because they affect the
-- visibility of operators in subsequent used packages.
U := Clause;
while Present (U) loop
if Nkind (U) = N_Use_Type_Clause then
End_Use_Type (U);
end if;
Next_Use_Clause (U);
end loop;
U := Clause;
while Present (U) loop
if Nkind (U) = N_Use_Package_Clause then
End_Use_Package (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;
function Is_Primitive_Operator_In_Use
(Op : Entity_Id;
F : Entity_Id) return Boolean;
-- Check whether Op is a primitive operator of a use-visible type
----------------------------------
-- Is_Primitive_Operator_In_Use --
----------------------------------
function Is_Primitive_Operator_In_Use
(Op : Entity_Id;
F : Entity_Id) return Boolean
is
T : constant Entity_Id := Base_Type (Etype (F));
begin
return In_Use (T) and then Scope (T) = Scope (Op);
end Is_Primitive_Operator_In_Use;
-- Start of processing for End_Use_Package
begin
Pack_Name := First (Names (N));
while Present (Pack_Name) loop
-- Test that Pack_Name actually denotes a package before processing
if Is_Entity_Name (Pack_Name)
and then Ekind (Entity (Pack_Name)) = E_Package
then
Pack := Entity (Pack_Name);
if In_Open_Scopes (Pack) then
null;
elsif not Redundant_Use (Pack_Name) then
Set_In_Use (Pack, False);
Set_Current_Use_Clause (Pack, Empty);
Id := First_Entity (Pack);
while Present (Id) loop
-- Preserve use-visibility of operators that are primitive
-- operators of a type that is use-visible through an active
-- use_type clause.
if Nkind (Id) = N_Defining_Operator_Symbol
and then
(Is_Primitive_Operator_In_Use
(Id, First_Formal (Id))
or else
(Present (Next_Formal (First_Formal (Id)))
and then
Is_Primitive_Operator_In_Use
(Id, 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);
Set_Current_Use_Clause (Renamed_Object (Pack), Empty);
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
declare
E : constant Entity_Id := Node (Elmt);
begin
-- Reset either Use_Visibility or Direct_Visibility, depending
-- on how the entity was hidden by the use clause.
if In_Use (Scope (E))
and then Used_As_Generic_Actual (Scope (E))
then
Set_Is_Potentially_Use_Visible (Node (Elmt));
else
Set_Is_Immediately_Visible (Node (Elmt));
end if;
Next_Elmt (Elmt);
end;
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
Elmt : Elmt_Id;
Id : Entity_Id;
T : Entity_Id;
-- Start of processing for End_Use_Type
begin
Id := First (Subtype_Marks (N));
while Present (Id) loop
-- A call to Rtsfind may occur while analyzing a use_type clause,
-- in which case the type marks are not resolved yet, and there is
-- nothing to remove.
if not Is_Entity_Name (Id) or else No (Entity (Id)) then
goto Continue;
end if;
T := Entity (Id);
if T = Any_Type or else From_With_Type (T) 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);
Set_Current_Use_Clause (T, Empty);
Set_Current_Use_Clause (Base_Type (T), Empty);
end if;
<<Continue>>
Next (Id);
end loop;
if Is_Empty_Elmt_List (Used_Operations (N)) then
return;
else
Elmt := First_Elmt (Used_Operations (N));
while Present (Elmt) loop
Set_Is_Potentially_Use_Visible (Node (Elmt), False);
Next_Elmt (Elmt);
end loop;
end if;
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 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.
Nvis_Is_Private_Subprg : Boolean := False;
-- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais
-- effect concerning library subprograms has been detected. Used to
-- generate the precise error message.
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 Is_Actual_Parameter return Boolean;
-- This function checks if the node N is an identifier that is an actual
-- parameter of a procedure call. If so it returns True, otherwise it
-- return False. The reason for this check is that at this stage we do
-- not know what procedure is being called if the procedure might be
-- overloaded, so it is premature to go setting referenced flags or
-- making calls to Generate_Reference. We will wait till Resolve_Actuals
-- for that processing
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;
-------------------------
-- Is_Actual_Parameter --
-------------------------
function Is_Actual_Parameter return Boolean is
begin
return
Nkind (N) = N_Identifier
and then
(Nkind (Parent (N)) = N_Procedure_Call_Statement
or else
(Nkind (Parent (N)) = N_Parameter_Association
and then N = Explicit_Actual_Parameter (Parent (N))
and then Nkind (Parent (Parent (N))) =
N_Procedure_Call_Statement));
end Is_Actual_Parameter;
-------------------------
-- 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
Comp_Unit : Node_Id;
Ent : Entity_Id;
Found : Boolean := False;
Hidden : Boolean := False;
Item : Node_Id;
begin
-- Ada 2005 (AI-262): Generate a precise error concerning the
-- Beaujolais effect that was previously detected
if Nvis_Is_Private_Subprg then
pragma Assert (Nkind (E2) = N_Defining_Identifier
and then Ekind (E2) = E_Function
and then Scope (E2) = Standard_Standard
and then Has_Private_With (E2));
-- Find the sloc corresponding to the private with'ed unit
Comp_Unit := Cunit (Current_Sem_Unit);
Error_Msg_Sloc := No_Location;
Item := First (Context_Items (Comp_Unit));
while Present (Item) loop
if Nkind (Item) = N_With_Clause
and then Private_Present (Item)
and then Entity (Name (Item)) = E2
then
Error_Msg_Sloc := Sloc (Item);
exit;
end if;
Next (Item);
end loop;
pragma Assert (Error_Msg_Sloc /= No_Location);
Error_Msg_N ("(Ada 2005): hidden by private with clause #", N);
return;
end if;
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 -- CODEFIX
("multiple use clauses cause hiding!", N);
Hidden := True;
end if;
Error_Msg_Sloc := Sloc (Ent);
Error_Msg_N -- CODEFIX
("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);
-- If the entity is declared in a generic package, it
-- cannot be visible, so there is no point in adding it
-- to the list of candidates if another homograph from a
-- non-generic package has been seen.
elsif Ekind (Scope (Ent)) = E_Generic_Package
and then Found
then
null;
else
Error_Msg_N -- CODEFIX
("non-visible declaration#!", N);
if Ekind (Scope (Ent)) /= E_Generic_Package then
Found := True;
end if;
if Is_Compilation_Unit (Ent)
and then
Nkind (Parent (Parent (N))) = N_Use_Package_Clause
then
Error_Msg_Qual_Level := 99;
Error_Msg_NE -- CODEFIX
("\\missing `WITH &;`", N, Ent);
Error_Msg_Qual_Level := 0;
end if;
if Ekind (Ent) = E_Discriminant
and then Present (Corresponding_Discriminant (Ent))
and then Scope (Corresponding_Discriminant (Ent)) =
Etype (Scope (Ent))
then
Error_Msg_N
("inherited discriminant not allowed here" &
" (RM 3.8 (12), 3.8.1 (6))!", N);
end if;
end if;
-- Set entity and its containing package as referenced. We
-- can't be sure of this, but this seems a better choice
-- to avoid unused entity messages.
if Comes_From_Source (Ent) then
Set_Referenced (Ent);
Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent)));
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
-- We should never find an undefined internal name. If we do, then
-- see if we have previous errors. If so, ignore on the grounds that
-- it is probably a cascaded message (e.g. a block label from a badly
-- formed block). If no previous errors, then we have a real internal
-- error of some kind so raise an exception.
if Is_Internal_Name (Chars (N)) then
if Total_Errors_Detected /= 0 then
return;
else
raise Program_Error;
end if;
end if;
-- 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
declare
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 not Is_Standard_Character_Type (Case_Typ)
then
Lit := First_Literal (Case_Typ);
Get_Name_String (Chars (Lit));
if Chars (Lit) /= Chars (N)
and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then
Error_Msg_Node_2 := Lit;
Error_Msg_N -- CODEFIX
("& 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 -- CODEFIX
("\\possible missing `WITH Ada.Text_'I'O; " &
"USE Ada.Text_'I'O`!", N);
-- Another special check if N is the prefix of a selected
-- component which is a known unit, add message complaining
-- about missing with for this unit.
elsif Nkind (Parent (N)) = N_Selected_Component
and then N = Prefix (Parent (N))
and then Is_Known_Unit (Parent (N))
then
Error_Msg_Node_2 := Selector_Name (Parent (N));
Error_Msg_N -- CODEFIX
("\\missing `WITH &.&;`", Prefix (Parent (N)));
end if;
-- Now check for possible misspellings
declare
E : Entity_Id;
Ematch : Entity_Id := Empty;
Last_Name_Id : constant Name_Id :=
Name_Id (Nat (First_Name_Id) +
Name_Entries_Count - 1);
begin
for Nam in First_Name_Id .. Last_Name_Id loop
E := Get_Name_Entity_Id (Nam);
if Present (E)
and then (Is_Immediately_Visible (E)
or else
Is_Potentially_Use_Visible (E))
then
if Is_Bad_Spelling_Of (Chars (N), Nam) then
Ematch := E;
exit;
end if;
end if;
end loop;
if Present (Ematch) then
Error_Msg_NE -- CODEFIX
("\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.Append (
(Node => N,
Err => Emsg,
Nvis => Nvis,
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);
-- Otherwise there is at least one entry on the homonym chain that
-- is reasonably considered as being known and non-visible.
else
Nvis_Messages;
end if;
return;
-- 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);
-- Ada 2005 (AI-262): Protect against a form of Beaujolais effect
-- that can occur in private_with clauses. Example:
-- with A;
-- private with B; package A is
-- package C is function B return Integer;
-- use A; end A;
-- V1 : Integer := B;
-- private function B return Integer;
-- V2 : Integer := B;
-- end C;
-- V1 resolves to A.B, but V2 resolves to library unit B
elsif Ekind (E2) = E_Function
and then Scope (E2) = Standard_Standard
and then Has_Private_With (E2)
then
Only_One_Visible := False;
All_Overloadable := False;
Nvis_Is_Private_Subprg := True;
exit;
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. Same if it is
-- declared in a local instantiation of the current instance.
else
if In_Instance then
-- Find current instance
Inst := Current_Scope;
while Present (Inst)
and then Inst /= Standard_Standard
loop
if Is_Generic_Instance (Inst) then
exit;
end if;
Inst := Scope (Inst);
end loop;
E2 := E;
while Present (E2) loop
if From_Actual_Package (E2)
or else
(Is_Generic_Instance (Scope (E2))
and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst))
then
E := E2;
goto Found;
end if;
E2 := Homonym (E2);
end loop;
Nvis_Messages;
return;
elsif
Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
then
-- A use-clause in the body of a system file creates conflict
-- with some entity in a user scope, while rtsfind is active.
-- Keep only the entity coming from another predefined unit.
E2 := E;
while Present (E2) loop
if Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Sloc (E2))))
then
E := E2;
goto Found;
end if;
E2 := Homonym (E2);
end loop;
-- Entity must exist because predefined unit is correct
raise Program_Error;
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 an 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
-- If a generic package contains a local declaration that
-- has the same name as the generic, there may be a visibility
-- conflict in an instance, where the local declaration must
-- also hide the name of the corresponding package renaming.
-- We check explicitly for a package declared by a renaming,
-- whose renamed entity is an instance that is on the scope
-- stack, and that contains a homonym in the same scope. Once
-- we have found it, we know that the package renaming is not
-- immediately visible, and that the identifier denotes the
-- other entity (and its homonyms if overloaded).
if Scope (E) = Scope (E2)
and then Ekind (E) = E_Package
and then Present (Renamed_Object (E))
and then Is_Generic_Instance (Renamed_Object (E))
and then In_Open_Scopes (Renamed_Object (E))
and then Comes_From_Source (N)
then
Set_Is_Immediately_Visible (E, False);
E := E2;
else
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;
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
-- Check violation of No_Wide_Characters restriction
Check_Wide_Character_Restriction (E, N);
-- When distribution features are available (Get_PCS_Name /=
-- Name_No_DSA), a remote access-to-subprogram type is converted
-- into a record type holding whatever information is needed to
-- perform a remote call on an RCI subprogram. In that case we
-- rewrite any occurrence of the RAS type into the equivalent record
-- type here. 'Access attribute references and RAS dereferences are
-- then implemented using specific TSSs. However when distribution is
-- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the
-- generation of these TSSs, and we must keep the RAS type in its
-- original access-to-subprogram form (since all calls through a
-- value of such type will be local anyway in the absence of a PCS).
if Comes_From_Source (N)
and then Is_Remote_Access_To_Subprogram_Type (E)
and then Expander_Active
and then Get_PCS_Name /= Name_No_DSA
then
Rewrite (N,
New_Occurrence_Of (Equivalent_Type (E), Sloc (N)));
return;
end if;
-- Set the entity. Note that the reason we call Set_Entity for the
-- overloadable case, as opposed to Set_Entity_With_Style_Check is
-- that in the overloaded case, the initial call can set the wrong
-- homonym. The call that sets the right homonym is in Sem_Res and
-- that call does use Set_Entity_With_Style_Check, so we don't miss
-- a style check.
if Is_Overloadable (E) then
Set_Entity (N, E);
else
Set_Entity_With_Style_Check (N, E);
end if;
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
if not Is_Actual_Parameter then
Generate_Reference (E, N);
end if;
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.
else
-- Entity is unambiguous, indicate that it is referenced here
-- For a renaming of an object, always generate simple reference,
-- we don't try to keep track of assignments in this case.
if Is_Object (E) and then Present (Renamed_Object (E)) then
Generate_Reference (E, N);
-- If the renamed entity is a private protected component,
-- reference the original component as well. This needs to be
-- done because the private renamings are installed before any
-- analysis has occurred. Reference to a private component will
-- resolve to the renaming and the original component will be
-- left unreferenced, hence the following.
if Is_Prival (E) then
Generate_Reference (Prival_Link (E), N);
end if;
-- One 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.
elsif Nkind (Parent (N)) = N_Label then
declare
R : constant Boolean := Referenced (E);
begin
-- Generate reference unless this is an actual parameter
-- (see comment below)
if Is_Actual_Parameter then
Generate_Reference (E, N);
Set_Referenced (E, R);
end if;
end;
-- Normal case, not a label: generate reference
-- ??? It is too early to generate a reference here even if the
-- entity is unambiguous, because the tree is not sufficiently
-- typed at this point for Generate_Reference to determine
-- whether this reference modifies the denoted object (because
-- implicit dereferences cannot be identified prior to full type
-- resolution).
-- The Is_Actual_Parameter routine takes care of one of these
-- cases but there are others probably ???
-- If the entity is the LHS of an assignment, and is a variable
-- (rather than a package prefix), we can mark it as a
-- modification right away, to avoid duplicate references.
else
if not Is_Actual_Parameter then
if Is_LHS (N)
and then Ekind (E) /= E_Package
and then Ekind (E) /= E_Generic_Package
then
Generate_Reference (E, N, 'm');
else
Generate_Reference (E, N);
end if;
end if;
Check_Nested_Access (E);
end if;
Set_Entity_Or_Discriminal (N, E);
-- The name may designate a generalized reference, in which case
-- the dereference interpretation will be included.
if Ada_Version >= Ada_2012
and then
(Nkind (Parent (N)) in N_Subexpr
or else Nkind_In (Parent (N), N_Object_Declaration,
N_Assignment_Statement))
then
Check_Implicit_Dereference (N, Etype (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
Selector : constant Node_Id := Selector_Name (N);
Candidate : Entity_Id := Empty;
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);
declare
Is_New_Candidate : Boolean;
begin
while Present (Id) loop
if Scope (Id) = P_Name then
Candidate := Id;
Is_New_Candidate := True;
-- Ada 2005 (AI-217): Handle shadow entities associated with types
-- declared in limited-withed nested packages. We don't need to
-- handle E_Incomplete_Subtype entities because the entities in
-- the limited view are always E_Incomplete_Type entities (see
-- Build_Limited_Views). Regarding the expression used to evaluate
-- the scope, it is important to note that the limited view also
-- has shadow entities associated nested packages. For this reason
-- the correct scope of the entity is the scope of the real entity
-- The non-limited view may itself be incomplete, in which case
-- get the full view if available.
elsif From_With_Type (Id)
and then Is_Type (Id)
and then Ekind (Id) = E_Incomplete_Type
and then Present (Non_Limited_View (Id))
and then Scope (Non_Limited_View (Id)) = P_Name
then
Candidate := Get_Full_View (Non_Limited_View (Id));
Is_New_Candidate := True;
else
Is_New_Candidate := False;
end if;
if Is_New_Candidate then
if Is_Child_Unit (Id) or else P_Name = Standard_Standard then
exit when Is_Visible_Lib_Unit (Id);
else
exit when not Is_Hidden (Id);
end if;
exit when Is_Immediately_Visible (Id);
end if;
Id := Homonym (Id);
end loop;
end;
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_Unit)
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 we know that the unit is a child unit we can give a more
-- accurate error message.
if Is_Child_Unit (Candidate) then
-- If the candidate is a private child unit and we are in
-- the visible part of a public unit, specialize the error
-- message. There might be a private with_clause for it,
-- but it is not currently active.
if Is_Private_Descendant (Candidate)
and then Ekind (Current_Scope) = E_Package
and then not In_Private_Part (Current_Scope)
and then not Is_Private_Descendant (Current_Scope)
then
Error_Msg_N ("private child unit& is not visible here",
Selector);
-- Normal case where we have a missing with for a child unit
else
Error_Msg_Qual_Level := 99;
Error_Msg_NE -- CODEFIX
("missing `WITH &;`", Selector, Candidate);
Error_Msg_Qual_Level := 0;
end if;
-- Here we don't know that this is a child unit
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_In (S, E_Function,
E_Package,
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 this is a selection from Ada, System or Interfaces, then
-- we assume a missing with for the corresponding package.
if Is_Known_Unit (N) then
if not Error_Posted (N) then
Error_Msg_Node_2 := Selector;
Error_Msg_N -- CODEFIX
("missing `WITH &.&;`", Prefix (N));
end if;
-- 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
-- The prefix may hide a homonym in the context that
-- declares the desired entity. This error can use a
-- specialized message.
if In_Open_Scopes (P_Name) then
declare
H : constant Entity_Id := Homonym (P_Name);
begin
if Present (H)
and then Is_Compilation_Unit (H)
and then
(Is_Immediately_Visible (H)
or else Is_Visible_Lib_Unit (H))
then
Id := First_Entity (H);
while Present (Id) loop
if Chars (Id) = Chars (Selector) then
Error_Msg_Qual_Level := 99;
Error_Msg_Name_1 := Chars (Selector);
Error_Msg_NE
("% not declared in&", N, P_Name);
Error_Msg_NE
("\use fully qualified name starting with "
& "Standard to make& visible", N, H);
Error_Msg_Qual_Level := 0;
goto Done;
end if;
Next_Entity (Id);
end loop;
end if;
-- If not found, standard error message
Error_Msg_NE ("& not declared in&", N, Selector);
<<Done>> null;
end;
else
Error_Msg_NE ("& not declared in&", N, Selector);
end if;
-- Check for misspelling of some entity in prefix
Id := First_Entity (P_Name);
while Present (Id) loop
if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector))
and then not Is_Internal_Name (Chars (Id))
then
Error_Msg_NE -- CODEFIX
("possible misspelling of&", Selector, Id);
exit;
end if;
Next_Entity (Id);
end loop;
-- 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_Node_2 := Selector;
Error_Msg_N -- CODEFIX
("\missing `WITH &.&;`", Prefix (N));
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)
and then Present (Equivalent_Type (Id))
then
-- If we are not actually generating distribution code (i.e. the
-- current PCS is the dummy non-distributed version), then the
-- Equivalent_Type will be missing, and Id should be treated as
-- a regular access-to-subprogram type.
Id := Equivalent_Type (Id);
Set_Chars (Selector, Chars (Id));
end if;
-- Ada 2005 (AI-50217): Check usage of entities in limited withed units
if Ekind (P_Name) = E_Package
and then From_With_Type (P_Name)
then
if From_With_Type (Id)
or else Is_Type (Id)
or else Ekind (Id) = E_Package
then
null;
else
Error_Msg_N
("limited withed package can only be used to access "
& "incomplete types",
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
-- If both the task type and the entry are in scope, this may still
-- be the expanded name of an entry formal.
if In_Open_Scopes (Id)
and then Nkind (Parent (N)) = N_Selected_Component
then
null;
else
-- 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;
end if;
Change_Selected_Component_To_Expanded_Name (N);
-- Do style check and generate reference, but skip both steps if this
-- entity has homonyms, since we may not have the right homonym set yet.
-- The proper homonym will be set during the resolve phase.
if Has_Homonym (Id) then
Set_Entity (N, Id);
else
Set_Entity_Or_Discriminal (N, Id);
if Is_LHS (N) then
Generate_Reference (Id, N, 'm');
else
Generate_Reference (Id, N);
end if;
end if;
if Is_Type (Id) then
Set_Etype (N, Id);
else
Set_Etype (N, Get_Full_View (Etype (Id)));
end if;
-- Check for violation of No_Wide_Characters
Check_Wide_Character_Restriction (Id, N);
-- 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)
and then
(not Is_Hidden (H)
or else Is_Immediately_Visible (H))
then
Collect_Interps (N);
exit;
end if;
H := Homonym (H);
end loop;
-- If an extension of System is present, collect possible explicit
-- overloadings declared in the extension.
if Chars (P_Name) = Name_System
and then Scope (P_Name) = Standard_Standard
and then Present (System_Extend_Unit)
and then Present_System_Aux (N)
then
H := Current_Entity (Id);
while Present (H) loop
if Scope (H) = System_Aux_Id then
Add_One_Interp (N, H, Etype (H));
end if;
H := Homonym (H);
end loop;
end if;
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;
-- If there is a single interpretation for N we can generate a
-- reference to the unique entity found.
if Is_Overloadable (Id) and then not Is_Overloaded (N) then
Generate_Reference (Id, N);
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
Ind : 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 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.
function Report_Overload return Entity_Id;
-- List possible interpretations, and specialize message in the
-- case of a generic actual.
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.
------------------------
-- 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 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;
begin
Sc := Scope (Inner);
while Sc /= Standard_Standard loop
if Sc = Outer then
return True;
else
Sc := Scope (Sc);
end if;
end loop;
return False;
end Within;
---------------------
-- Report_Overload --
---------------------
function Report_Overload return Entity_Id is
begin
if Is_Actual then
Error_Msg_NE -- CODEFIX
("ambiguous actual subprogram&, " &
"possible interpretations:", N, Nam);
else
Error_Msg_N -- CODEFIX
("ambiguous subprogram, " &
"possible interpretations:", N);
end if;
List_Interps (Nam, N);
return Old_S;
end Report_Overload;
-- Start of processing for Find_Renamed_Entity
begin
Old_S := Any_Id;
Candidate_Renaming := Empty;
if not Is_Overloaded (Nam) then
if Entity_Matches_Spec (Entity (Nam), New_S) then
Candidate_Renaming := New_S;
if Is_Visible_Operation (Entity (Nam)) then
Old_S := Entity (Nam);
end if;
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, Ind, 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, Ind, Etype (Old_S));
if It1 = No_Interp then
Inst := Enclosing_Instance;
if Present (Inst) then
if Within (It.Nam, Inst) then
if Within (Old_S, Inst) then
-- Choose the innermost subprogram, which would
-- have hidden the outer one in the generic.
if Scope_Depth (It.Nam) <
Scope_Depth (Old_S)
then
return Old_S;
else
return It.Nam;
end if;
end if;
elsif Within (Old_S, Inst) then
return (Old_S);
else
return Report_Overload;
end if;
-- If not within an instance, ambiguity is real
else
return Report_Overload;
end if;
else
Old_S := It1.Nam;
exit;
end if;
else
I1 := Ind;
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 (Ind, It);
end loop;
Set_Entity (Nam, Old_S);
if Old_S /= Any_Id then
Set_Is_Overloaded (Nam, False);
end if;
end if;
return Old_S;
end Find_Renamed_Entity;
-----------------------------
-- Find_Selected_Component --
-----------------------------
procedure Find_Selected_Component (N : Node_Id) is
P : constant 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;
end if;
-- Selector name cannot be a character literal or an operator symbol in
-- SPARK, except for the operator symbol in a renaming.
if Restriction_Check_Required (SPARK) then
if Nkind (Selector_Name (N)) = N_Character_Literal then
Check_SPARK_Restriction
("character literal cannot be prefixed", N);
elsif Nkind (Selector_Name (N)) = N_Operator_Symbol
and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
then
Check_SPARK_Restriction ("operator symbol cannot be prefixed", N);
end if;
end if;
-- 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).
if Present (Entity (Selector_Name (N))) then
if No (Etype (N))
or else Etype (N) = Any_Type
then
declare
Sel_Name : constant Node_Id := Selector_Name (N);
Selector : constant 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);
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
-- Do not build the subtype when referencing components of
-- dispatch table wrappers. Required to avoid generating
-- elaboration code with HI runtimes. JVM and .NET use a
-- modified version of Ada.Tags which does not contain RE_
-- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper.
-- Avoid raising RE_Not_Available exception in those cases.
if VM_Target = No_VM
and then RTU_Loaded (Ada_Tags)
and then
((RTE_Available (RE_Dispatch_Table_Wrapper)
and then Scope (Selector) =
RTE (RE_Dispatch_Table_Wrapper))
or else
(RTE_Available (RE_No_Dispatch_Table_Wrapper)
and then Scope (Selector) =
RTE (RE_No_Dispatch_Table_Wrapper)))
then
C_Etype := Empty;
else
C_Etype :=
Build_Actual_Subtype_Of_Component
(Etype (Selector), N);
end if;
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 : constant 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.
-- ??? Could we rewrite an implicit dereference into an explicit
-- one here?
Analyze_Selected_Component (N);
-- Reference to type name in predicate/invariant expression
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_In (P_Name, E_Procedure, 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;
Ind : Interp_Index;
It : Interp;
begin
Get_First_Interp (P, Ind, 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 (Ind, 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 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_Selected_Component_To_Expanded_Name (N);
Set_Entity (N, Any_Id);
Set_Etype (N, Any_Type);
-- 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);
if Is_Access_Type (P_Type)
and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type
then
Error_Msg_N
("\dereference must not be of an incomplete type " &
"(RM 3.10.1)", P);
end if;
else
Error_Msg_N (
"invalid prefix in selected component", P);
end if;
end if;
-- Selector name is restricted in SPARK
if Nkind (N) = N_Expanded_Name
and then Restriction_Check_Required (SPARK)
then
if Is_Subprogram (P_Name) then
Check_SPARK_Restriction
("prefix of expanded name cannot be a subprogram", P);
elsif Ekind (P_Name) = E_Loop then
Check_SPARK_Restriction
("prefix of expanded name cannot be a loop statement", 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;
Analyze_Dimension (N);
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 not valid in Ada 83 mode, but we do not
-- need to enforce that at this point, since the declaration of the
-- tagged type in the prefix would have been flagged already.
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 where type is not known to be tagged. Its appearance in
-- the prefix of the 'Class attribute indicates that the full view
-- will be tagged.
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.
-- In Ada 2005 this usage is declared obsolescent, so we
-- warn accordingly. This usage is only legal if the type
-- is completed in the current scope, and not for a limited
-- view of a type.
if Ada_Version >= Ada_2005 then
-- Test whether the Available_View of a limited type view
-- is tagged, since the limited view may not be marked as
-- tagged if the type itself has an untagged incomplete
-- type view in its package.
if From_With_Type (T)
and then not Is_Tagged_Type (Available_View (T))
then
Error_Msg_N
("prefix of Class attribute must be tagged", N);
Set_Etype (N, Any_Type);
Set_Entity (N, Any_Type);
return;
-- ??? This test is temporarily disabled (always
-- False) because it causes an unwanted warning on
-- GNAT sources (built with -gnatg, which includes
-- Warn_On_Obsolescent_ Feature). Once this issue
-- is cleared in the sources, it can be enabled.
elsif Warn_On_Obsolescent_Feature
and then False
then
Error_Msg_N
("applying 'Class to an untagged incomplete type"
& " is an obsolescent feature (RM J.11)?r?", N);
end if;
end if;
Set_Is_Tagged_Type (T);
Set_Direct_Primitive_Operations (T, New_Elmt_List);
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 No (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
if Is_Concurrent_Type (T) then
if No (Corresponding_Record_Type (Entity (Prefix (N)))) then
-- Previous error. Use current type, which at least
-- provides some operations.
C := Entity (Prefix (N));
else
C := Class_Wide_Type
(Corresponding_Record_Type (Entity (Prefix (N))));
end if;
else
C := Class_Wide_Type (Entity (Prefix (N)));
end if;
Set_Entity_With_Style_Check (N, C);
Generate_Reference (C, N);
Set_Etype (N, C);
end if;
-- Base attribute, not allowed in Ada 83
elsif Attribute_Name (N) = Name_Base then
Error_Msg_Name_1 := Name_Base;
Check_SPARK_Restriction
("attribute% is only allowed as prefix of another attribute", N);
if Ada_Version = 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 Ada_Version >= Ada_95
and then not Is_Scalar_Type (Typ)
and then not Is_Generic_Type (Typ)
then
Error_Msg_N
("prefix of Base attribute must be scalar type",
Prefix (N));
elsif Warn_On_Redundant_Constructs
and then Base_Type (Typ) = Typ
then
Error_Msg_NE -- CODEFIX
("redundant attribute, & is its own base type?r?", N, Typ);
end if;
T := Base_Type (Typ);
-- Rewrite attribute reference with type itself (see similar
-- processing in Analyze_Attribute, case Base). Preserve prefix
-- if present, for other legality checks.
if Nkind (Prefix (N)) = N_Expanded_Name then
Rewrite (N,
Make_Expanded_Name (Sloc (N),
Chars => Chars (T),
Prefix => New_Copy (Prefix (Prefix (N))),
Selector_Name => New_Reference_To (T, Sloc (N))));
else
Rewrite (N, New_Reference_To (T, Sloc (N)));
end if;
Set_Entity (N, T);
Set_Etype (N, T);
end if;
elsif Attribute_Name (N) = Name_Stub_Type then
-- This is handled in Analyze_Attribute
Analyze (N);
-- 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
-- If the type is an incomplete type created to handle
-- anonymous access components of a record type, then the
-- incomplete type is the visible entity and subsequent
-- references will point to it. Mark the original full
-- type as referenced, to prevent spurious warnings.
if Is_Incomplete_Type (T_Name)
and then Present (Full_View (T_Name))
and then not Comes_From_Source (T_Name)
then
Set_Referenced (Full_View (T_Name));
end if;
T_Name := Get_Full_View (T_Name);
-- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through
-- limited-with clauses
if From_With_Type (T_Name)
and then Ekind (T_Name) in Incomplete_Kind
and then Present (Non_Limited_View (T_Name))
and then Is_Interface (Non_Limited_View (T_Name))
then
T_Name := Non_Limited_View (T_Name);
end if;
if In_Open_Scopes (T_Name) then
if Ekind (Base_Type (T_Name)) = E_Task_Type then
-- In Ada 2005, a task name can be used in an access
-- definition within its own body. It cannot be used
-- in the discriminant part of the task declaration,
-- nor anywhere else in the declaration because entries
-- cannot have access parameters.
if Ada_Version >= Ada_2005
and then Nkind (Parent (N)) = N_Access_Definition
then
Set_Entity (N, T_Name);
Set_Etype (N, T_Name);
if Has_Completion (T_Name) then
return;
else
Error_Msg_N
("task type cannot be used as type mark " &
"within its own declaration", N);
end if;
else
Error_Msg_N
("task type cannot be used as type mark " &
"within its own spec or body", N);
end if;
elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then
-- In Ada 2005, a protected name can be used in an access
-- definition within its own body.
if Ada_Version >= Ada_2005
and then Nkind (Parent (N)) = N_Access_Definition
then
Set_Entity (N, T_Name);
Set_Etype (N, T_Name);
return;
else
Error_Msg_N
("protected type cannot be used as type mark " &
"within its own spec or body", N);
end if;
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)) and then Comes_From_Source (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;
------------------------------------
-- 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_Standard_Character_Type (Id) and then Is_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_Private_With --
----------------------
function Has_Private_With (E : Entity_Id) return Boolean is
Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit);
Item : Node_Id;
begin
Item := First (Context_Items (Comp_Unit));
while Present (Item) loop
if Nkind (Item) = N_With_Clause
and then Private_Present (Item)
and then Entity (Name (Item)) = E
then
return True;
end if;
Next (Item);
end loop;
return False;
end Has_Private_With;
---------------------------
-- 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;
Op_Type : Entity_Id := Empty);
-- Add implicit interpretation to node N, using the type for which a
-- predefined operator exists. If the operator yields a boolean type,
-- the Operand_Type is implicitly referenced by the operator, and a
-- reference to it must be generated.
---------------------------
-- Add_Implicit_Operator --
---------------------------
procedure Add_Implicit_Operator
(T : Entity_Id;
Op_Type : Entity_Id := Empty)
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;
-- If the context is an unanalyzed function call, determine whether
-- a binary or unary interpretation is required.
if Nkind (Parent (N)) = N_Indexed_Component then
declare
Is_Binary_Call : constant Boolean :=
Present
(Next (First (Expressions (Parent (N)))));
Is_Binary_Op : constant Boolean :=
First_Entity
(Predef_Op) /= Last_Entity (Predef_Op);
Predef_Op2 : constant Entity_Id := Homonym (Predef_Op);
begin
if Is_Binary_Call then
if Is_Binary_Op then
Add_One_Interp (N, Predef_Op, T);
else
Add_One_Interp (N, Predef_Op2, T);
end if;
else
if not Is_Binary_Op then
Add_One_Interp (N, Predef_Op, T);
else
Add_One_Interp (N, Predef_Op2, T);
end if;
end if;
end;
else
Add_One_Interp (N, Predef_Op, T);
-- For operators with unary and binary interpretations, if
-- context is not a call, add both
if Present (Homonym (Predef_Op)) then
Add_One_Interp (N, Homonym (Predef_Op), T);
end if;
end if;
-- The node is a reference to a predefined operator, and
-- an implicit reference to the type of its operands.
if Present (Op_Type) then
Generate_Operator_Reference (N, Op_Type);
else
Generate_Operator_Reference (N, 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 Is_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 Is_Base_Type (Id)
then
Add_Implicit_Operator (Standard_Boolean, Id);
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 Is_Base_Type (Id)
then
Add_Implicit_Operator (Standard_Boolean, Id);
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 Is_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 Is_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;
-----------------------------------
-- Has_Loop_In_Inner_Open_Scopes --
-----------------------------------
function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is
begin
-- Several scope stacks are maintained by Scope_Stack. The base of the
-- currently active scope stack is denoted by the Is_Active_Stack_Base
-- flag in the scope stack entry. Note that the scope stacks used to
-- simply be delimited implicitly by the presence of Standard_Standard
-- at their base, but there now are cases where this is not sufficient
-- because Standard_Standard actually may appear in the middle of the
-- active set of scopes.
for J in reverse 0 .. Scope_Stack.Last loop
-- S was reached without seing a loop scope first
if Scope_Stack.Table (J).Entity = S then
return False;
-- S was not yet reached, so it contains at least one inner loop
elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then
return True;
end if;
-- Check Is_Active_Stack_Base to tell us when to stop, as 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.
pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base);
end loop;
raise Program_Error; -- unreachable
end Has_Loop_In_Inner_Open_Scopes;
--------------------
-- In_Open_Scopes --
--------------------
function In_Open_Scopes (S : Entity_Id) return Boolean is
begin
-- Several scope stacks are maintained by Scope_Stack. The base of the
-- currently active scope stack is denoted by the Is_Active_Stack_Base
-- flag in the scope stack entry. Note that the scope stacks used to
-- simply be delimited implicitly by the presence of Standard_Standard
-- at their base, but there now are cases where this is not sufficient
-- because Standard_Standard actually may appear in the middle of the
-- active set of scopes.
for J in reverse 0 .. Scope_Stack.Last loop
if Scope_Stack.Table (J).Entity = S then
return True;
end if;
-- Check Is_Active_Stack_Base to tell us when to stop, as 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_In (Old_S, E_Function, 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;
Force_Installation : Boolean := False)
is
U : Node_Id;
P : Node_Id;
Id : Entity_Id;
begin
U := Clause;
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
Note_Redundant_Use (P);
elsif Present (Renamed_Object (Id))
and then In_Use (Renamed_Object (Id))
then
Note_Redundant_Use (P);
elsif Force_Installation or else Applicable_Use (P) then
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 not Is_Entity_Name (P)
or else No (Entity (P))
then
null;
elsif Entity (P) /= Any_Type then
Use_One_Type (P);
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).
--------------------
-- Has_Components --
--------------------
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))
or else (Is_Incomplete_Type (T1)
and then From_With_Type (T1)
and then Present (Non_Limited_View (T1))
and then Is_Record_Type
(Get_Full_View (Non_Limited_View (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;
------------------------
-- Note_Redundant_Use --
------------------------
procedure Note_Redundant_Use (Clause : Node_Id) is
Pack_Name : constant Entity_Id := Entity (Clause);
Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name);
Decl : constant Node_Id := Parent (Clause);
Prev_Use : Node_Id := Empty;
Redundant : Node_Id := Empty;
-- The Use_Clause which is actually redundant. In the simplest case it
-- is Pack itself, but when we compile a body we install its context
-- before that of its spec, in which case it is the use_clause in the
-- spec that will appear to be redundant, and we want the warning to be
-- placed on the body. Similar complications appear when the redundancy
-- is between a child unit and one of its ancestors.
begin
Set_Redundant_Use (Clause, True);
if not Comes_From_Source (Clause)
or else In_Instance
or else not Warn_On_Redundant_Constructs
then
return;
end if;
if not Is_Compilation_Unit (Current_Scope) then
-- If the use_clause is in an inner scope, it is made redundant by
-- some clause in the current context, with one exception: If we're
-- compiling a nested package body, and the use_clause comes from the
-- corresponding spec, the clause is not necessarily fully redundant,
-- so we should not warn. If a warning was warranted, it would have
-- been given when the spec was processed.
if Nkind (Parent (Decl)) = N_Package_Specification then
declare
Package_Spec_Entity : constant Entity_Id :=
Defining_Unit_Name (Parent (Decl));
begin
if In_Package_Body (Package_Spec_Entity) then
return;
end if;
end;
end if;
Redundant := Clause;
Prev_Use := Cur_Use;
elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
declare
Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use);
New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause);
Scop : Entity_Id;
begin
if Cur_Unit = New_Unit then
-- Redundant clause in same body
Redundant := Clause;
Prev_Use := Cur_Use;
elsif Cur_Unit = Current_Sem_Unit then
-- If the new clause is not in the current unit it has been
-- analyzed first, and it makes the other one redundant.
-- However, if the new clause appears in a subunit, Cur_Unit
-- is still the parent, and in that case the redundant one
-- is the one appearing in the subunit.
if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then
Redundant := Clause;
Prev_Use := Cur_Use;
-- Most common case: redundant clause in body,
-- original clause in spec. Current scope is spec entity.
elsif
Current_Scope =
Defining_Entity (
Unit (Library_Unit (Cunit (Current_Sem_Unit))))
then
Redundant := Cur_Use;
Prev_Use := Clause;
else
-- The new clause may appear in an unrelated unit, when
-- the parents of a generic are being installed prior to
-- instantiation. In this case there must be no warning.
-- We detect this case by checking whether the current top
-- of the stack is related to the current compilation.
Scop := Current_Scope;
while Present (Scop)
and then Scop /= Standard_Standard
loop
if Is_Compilation_Unit (Scop)
and then not Is_Child_Unit (Scop)
then
return;
elsif Scop = Cunit_Entity (Current_Sem_Unit) then
exit;
end if;
Scop := Scope (Scop);
end loop;
Redundant := Cur_Use;
Prev_Use := Clause;
end if;
elsif New_Unit = Current_Sem_Unit then
Redundant := Clause;
Prev_Use := Cur_Use;
else
-- Neither is the current unit, so they appear in parent or
-- sibling units. Warning will be emitted elsewhere.
return;
end if;
end;
elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit))))
then
-- Use_clause is in child unit of current unit, and the child unit
-- appears in the context of the body of the parent, so it has been
-- installed first, even though it is the redundant one. Depending on
-- their placement in the context, the visible or the private parts
-- of the two units, either might appear as redundant, but the
-- message has to be on the current unit.
if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then
Redundant := Cur_Use;
Prev_Use := Clause;
else
Redundant := Clause;
Prev_Use := Cur_Use;
end if;
-- If the new use clause appears in the private part of a parent unit
-- it may appear to be redundant w.r.t. a use clause in a child unit,
-- but the previous use clause was needed in the visible part of the
-- child, and no warning should be emitted.
if Nkind (Parent (Decl)) = N_Package_Specification
and then
List_Containing (Decl) = Private_Declarations (Parent (Decl))
then
declare
Par : constant Entity_Id := Defining_Entity (Parent (Decl));
Spec : constant Node_Id :=
Specification (Unit (Cunit (Current_Sem_Unit)));
begin
if Is_Compilation_Unit (Par)
and then Par /= Cunit_Entity (Current_Sem_Unit)
and then Parent (Cur_Use) = Spec
and then
List_Containing (Cur_Use) = Visible_Declarations (Spec)
then
return;
end if;
end;
end if;
-- Finally, if the current use clause is in the context then
-- the clause is redundant when it is nested within the unit.
elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit
and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit
and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause)
then
Redundant := Clause;
Prev_Use := Cur_Use;
else
null;
end if;
if Present (Redundant) then
Error_Msg_Sloc := Sloc (Prev_Use);
Error_Msg_NE -- CODEFIX
("& is already use-visible through previous use clause #??",
Redundant, Pack_Name);
end if;
end Note_Redundant_Use;
---------------
-- Pop_Scope --
---------------
procedure Pop_Scope is
SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
S : constant Entity_Id := SST.Entity;
begin
if Debug_Flag_E then
Write_Info;
end if;
-- Set Default_Storage_Pool field of the library unit if necessary
if Ekind_In (S, E_Package, E_Generic_Package)
and then
Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit
then
declare
Aux : constant Node_Id :=
Aux_Decls_Node (Parent (Unit_Declaration_Node (S)));
begin
if No (Default_Storage_Pool (Aux)) then
Set_Default_Storage_Pool (Aux, Default_Pool);
end if;
end;
end if;
Scope_Suppress := SST.Save_Scope_Suppress;
Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top;
Check_Policy_List := SST.Save_Check_Policy_List;
Default_Pool := SST.Save_Default_Storage_Pool;
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 (SST.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 (and we do the abort even with assertions off since the
-- penalty is incorrect code generation).
if SST.Actions_To_Be_Wrapped_Before /= No_List
or else
SST.Actions_To_Be_Wrapped_After /= No_List
then
raise Program_Error;
end if;
-- Free last subprogram name if allocated, and pop scope
Free (SST.Last_Subprogram_Name);
Scope_Stack.Decrement_Last;
end Pop_Scope;
---------------
-- Push_Scope --
---------------
procedure Push_Scope (S : Entity_Id) is
E : constant Entity_Id := Scope (S);
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;
declare
SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last);
begin
SST.Entity := S;
SST.Save_Scope_Suppress := Scope_Suppress;
SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top;
SST.Save_Check_Policy_List := Check_Policy_List;
SST.Save_Default_Storage_Pool := Default_Pool;
if Scope_Stack.Last > Scope_Stack.First then
SST.Component_Alignment_Default := Scope_Stack.Table
(Scope_Stack.Last - 1).
Component_Alignment_Default;
end if;
SST.Last_Subprogram_Name := null;
SST.Is_Transient := False;
SST.Node_To_Be_Wrapped := Empty;
SST.Pending_Freeze_Actions := No_List;
SST.Actions_To_Be_Wrapped_Before := No_List;
SST.Actions_To_Be_Wrapped_After := No_List;
SST.First_Use_Clause := Empty;
SST.Is_Active_Stack_Base := False;
SST.Previous_Visibility := False;
end;
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;
-- Deal with copying flags from the previous scope to this one. This is
-- not necessary if either scope is standard, or if the new scope is a
-- child unit.
if S /= Standard_Standard
and then Scope (S) /= Standard_Standard
and then not Is_Child_Unit (S)
then
if Nkind (E) not in N_Entity then
return;
end if;
-- Copy categorization flags from Scope (S) to S, this is not done
-- when Scope (S) is Standard_Standard since propagation is from
-- library unit entity inwards. Copy other relevant attributes as
-- well (Discard_Names in particular).
-- 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_Preelaborated (S, Is_Preelaborated (E));
Set_Is_Shared_Passive (S, Is_Shared_Passive (E));
Set_Discard_Names (S, Discard_Names (E));
Set_Suppress_Value_Tracking_On_Call
(S, Suppress_Value_Tracking_On_Call (E));
Set_Categorization_From_Scope (E => S, Scop => E);
end if;
end if;
if Is_Child_Unit (S)
and then Present (E)
and then Ekind_In (E, E_Package, E_Generic_Package)
and then
Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
then
declare
Aux : constant Node_Id :=
Aux_Decls_Node (Parent (Unit_Declaration_Node (E)));
begin
if Present (Default_Storage_Pool (Aux)) then
Default_Pool := Default_Storage_Pool (Aux);
end if;
end;
end if;
end Push_Scope;
---------------------
-- Premature_Usage --
---------------------
procedure Premature_Usage (N : Node_Id) is
Kind : constant 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);
elsif Kind = N_Full_Type_Declaration then
Error_Msg_N
("type& 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 : Unit_Name_Type;
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 with_clause
-- for System.
-----------------
-- Find_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_Unit) 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_Unit)));
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_Unit));
Error_Msg_N
("extension package `%.%` does not exist",
Opt.System_Extend_Unit);
return False;
end if;
end if;
end Present_System_Aux;
-------------------------
-- Restore_Scope_Stack --
-------------------------
procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is
E : Entity_Id;
S : Entity_Id;
Comp_Unit : Node_Id;
In_Child : Boolean := False;
Full_Vis : Boolean := True;
SS_Last : constant Int := Scope_Stack.Last;
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
if not From_With_Type (E) then
Set_Is_Immediately_Visible (E,
Is_Visible_Lib_Unit (E) or else In_Open_Scopes (E));
else
pragma Assert
(Nkind (Parent (E)) = N_Defining_Program_Unit_Name
and then
Nkind (Parent (Parent (E))) = N_Package_Specification);
Set_Is_Immediately_Visible (E,
Limited_View_Installed (Parent (Parent (E))));
end if;
else
Set_Is_Immediately_Visible (E, True);
end if;
Next_Entity (E);
if not Full_Vis
and then Is_Package_Or_Generic_Package (S)
then
-- We are in the visible part of the package scope
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 then
while Present (E) loop
if Is_Child_Unit (E) then
Set_Is_Immediately_Visible (E,
Is_Visible_Lib_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 Is_Package_Or_Generic_Package (S)
and then (In_Private_Part (S) or else In_Package_Body (S))
then
Full_Vis := True;
-- if S is the scope of some instance (which has already been
-- seen on the stack) it does not affect the visibility of
-- other scopes.
elsif Is_Hidden_Open_Scope (S) then
null;
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;
if SS_Last >= Scope_Stack.First
and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard
and then Handle_Use
then
Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
end if;
end Restore_Scope_Stack;
----------------------
-- Save_Scope_Stack --
----------------------
procedure Save_Scope_Stack (Handle_Use : Boolean := True) 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 Handle_Use then
End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause);
end if;
-- 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);
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;
Private_With_OK : Boolean := False;
begin
if Ekind (P) /= E_Package then
return;
end if;
Set_In_Use (P);
Set_Current_Use_Clause (P, N);
-- Ada 2005 (AI-50217): Check restriction
if From_With_Type (P) then
Error_Msg_N ("limited withed 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));
Set_Current_Use_Clause (Renamed_Object (P), N);
Real_P := Renamed_Object (P);
else
Real_P := P;
end if;
-- Ada 2005 (AI-262): Check the use_clause of a private withed package
-- found in the private part of a package specification
if In_Private_Part (Current_Scope)
and then Has_Private_With (P)
and then Is_Child_Unit (Current_Scope)
and then Is_Child_Unit (P)
and then Is_Ancestor_Package (Scope (Current_Scope), P)
then
Private_With_OK := True;
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)
or else Private_With_OK) -- Ada 2005 (AI-262)
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. similarly, an entity that is
-- declared in an enclosing instance will not be hidden by an
-- an entity declared in a generic actual, which can only have
-- been use-visible in the generic and will not have hidden the
-- entity in the generic parent.
-- If Id is called Standard, the predefined package with the
-- same name is in the homonym chain. It has to be ignored
-- because it has no defined scope (being the only entity in
-- the system with this mandated behavior).
elsif not Is_Hidden (Id)
and then Present (Scope (Prev))
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
if In_Open_Scopes (Scope (Prev))
and then Is_Generic_Instance (Scope (Prev))
and then Present (Associated_Formal_Package (P))
then
null;
else
Set_Is_Potentially_Use_Visible (Id);
Set_Is_Immediately_Visible (Prev, False);
Append_Elmt (Prev, Hidden_By_Use_Clause (N));
end if;
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 (multiply
-- and divide) 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;
-- In an instance, two homonyms may become use_visible through the
-- actuals of distinct formal packages. In the generic, only the
-- current one would have been visible, so make the other one
-- not use_visible.
elsif Present (Current_Instance)
and then Is_Potentially_Use_Visible (Prev)
and then not Is_Overloadable (Prev)
and then Scope (Id) /= Scope (Prev)
and then Used_As_Generic_Actual (Scope (Prev))
and then Used_As_Generic_Actual (Scope (Id))
and then not In_Same_List (Current_Use_Clause (Scope (Prev)),
Current_Use_Clause (Scope (Id)))
then
Set_Is_Potentially_Use_Visible (Prev, False);
Append_Elmt (Prev, Hidden_By_Use_Clause (N));
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_Lib_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_Lib_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; Installed : Boolean := False) is
Elmt : Elmt_Id;
Is_Known_Used : Boolean;
Op_List : Elist_Id;
T : Entity_Id;
function Spec_Reloaded_For_Body return Boolean;
-- Determine whether the compilation unit is a package body and the use
-- type clause is in the spec of the same package. Even though the spec
-- was analyzed first, its context is reloaded when analysing the body.
procedure Use_Class_Wide_Operations (Typ : Entity_Id);
-- AI05-150: if the use_type_clause carries the "all" qualifier,
-- class-wide operations of ancestor types are use-visible if the
-- ancestor type is visible.
----------------------------
-- Spec_Reloaded_For_Body --
----------------------------
function Spec_Reloaded_For_Body return Boolean is
begin
if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then
declare
Spec : constant Node_Id :=
Parent (List_Containing (Parent (Id)));
begin
-- Check whether type is declared in a package specification,
-- and current unit is the corresponding package body. The
-- use clauses themselves may be within a nested package.
return
Nkind (Spec) = N_Package_Specification
and then
In_Same_Source_Unit (Corresponding_Body (Parent (Spec)),
Cunit_Entity (Current_Sem_Unit));
end;
end if;
return False;
end Spec_Reloaded_For_Body;
-------------------------------
-- Use_Class_Wide_Operations --
-------------------------------
procedure Use_Class_Wide_Operations (Typ : Entity_Id) is
Scop : Entity_Id;
Ent : Entity_Id;
function Is_Class_Wide_Operation_Of
(Op : Entity_Id;
T : Entity_Id) return Boolean;
-- Determine whether a subprogram has a class-wide parameter or
-- result that is T'Class.
---------------------------------
-- Is_Class_Wide_Operation_Of --
---------------------------------
function Is_Class_Wide_Operation_Of
(Op : Entity_Id;
T : Entity_Id) return Boolean
is
Formal : Entity_Id;
begin
Formal := First_Formal (Op);
while Present (Formal) loop
if Etype (Formal) = Class_Wide_Type (T) then
return True;
end if;
Next_Formal (Formal);
end loop;
if Etype (Op) = Class_Wide_Type (T) then
return True;
end if;
return False;
end Is_Class_Wide_Operation_Of;
-- Start of processing for Use_Class_Wide_Operations
begin
Scop := Scope (Typ);
if not Is_Hidden (Scop) then
Ent := First_Entity (Scop);
while Present (Ent) loop
if Is_Overloadable (Ent)
and then Is_Class_Wide_Operation_Of (Ent, Typ)
and then not Is_Potentially_Use_Visible (Ent)
then
Set_Is_Potentially_Use_Visible (Ent);
Append_Elmt (Ent, Used_Operations (Parent (Id)));
end if;
Next_Entity (Ent);
end loop;
end if;
if Is_Derived_Type (Typ) then
Use_Class_Wide_Operations (Etype (Base_Type (Typ)));
end if;
end Use_Class_Wide_Operations;
-- Start of processing for Use_One_Type
begin
-- It is the type determined by the subtype mark (8.4(8)) whose
-- operations become potentially use-visible.
T := Base_Type (Entity (Id));
-- Either the type itself is used, the package where it is declared
-- is in use or the entity is declared in the current package, thus
-- use-visible.
Is_Known_Used :=
In_Use (T)
or else In_Use (Scope (T))
or else Scope (T) = Current_Scope;
Set_Redundant_Use (Id,
Is_Known_Used or else Is_Potentially_Use_Visible (T));
if Ekind (T) = E_Incomplete_Type then
Error_Msg_N ("premature usage of incomplete type", Id);
elsif In_Open_Scopes (Scope (T)) then
null;
-- A limited view cannot appear in a use_type clause. However, an access
-- type whose designated type is limited has the flag but is not itself
-- a limited view unless we only have a limited view of its enclosing
-- package.
elsif From_With_Type (T)
and then From_With_Type (Scope (T))
then
Error_Msg_N
("incomplete type from limited view "
& "cannot appear in use clause", Id);
-- If the subtype mark designates a subtype in a different package,
-- we have to check that the parent type is visible, otherwise the
-- use type clause is a noop. Not clear how to do that???
elsif not Redundant_Use (Id) then
Set_In_Use (T);
-- If T is tagged, primitive operators on class-wide operands
-- are also available.
if Is_Tagged_Type (T) then
Set_In_Use (Class_Wide_Type (T));
end if;
Set_Current_Use_Clause (T, Parent (Id));
-- Iterate over primitive operations of the type. If an operation is
-- already use_visible, it is the result of a previous use_clause,
-- and already appears on the corresponding entity chain. If the
-- clause is being reinstalled, operations are already use-visible.
if Installed then
null;
else
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))
and then not Is_Potentially_Use_Visible (Node (Elmt))
then
Set_Is_Potentially_Use_Visible (Node (Elmt));
Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
elsif Ada_Version >= Ada_2012
and then All_Present (Parent (Id))
and then not Is_Hidden (Node (Elmt))
and then not Is_Potentially_Use_Visible (Node (Elmt))
then
Set_Is_Potentially_Use_Visible (Node (Elmt));
Append_Elmt (Node (Elmt), Used_Operations (Parent (Id)));
end if;
Next_Elmt (Elmt);
end loop;
end if;
if Ada_Version >= Ada_2012
and then All_Present (Parent (Id))
and then Is_Tagged_Type (T)
then
Use_Class_Wide_Operations (T);
end if;
end if;
-- If warning on redundant constructs, check for unnecessary WITH
if Warn_On_Redundant_Constructs
and then Is_Known_Used
-- with P; with P; use P;
-- package P is package X is package body X is
-- type T ... use P.T;
-- The compilation unit is the body of X. GNAT first compiles the
-- spec of X, then proceeds to the body. At that point P is marked
-- as use visible. The analysis then reinstalls the spec along with
-- its context. The use clause P.T is now recognized as redundant,
-- but in the wrong context. Do not emit a warning in such cases.
-- Do not emit a warning either if we are in an instance, there is
-- no redundancy between an outer use_clause and one that appears
-- within the generic.
and then not Spec_Reloaded_For_Body
and then not In_Instance
then
-- The type already has a use clause
if In_Use (T) then
-- Case where we know the current use clause for the type
if Present (Current_Use_Clause (T)) then
Use_Clause_Known : declare
Clause1 : constant Node_Id := Parent (Id);
Clause2 : constant Node_Id := Current_Use_Clause (T);
Ent1 : Entity_Id;
Ent2 : Entity_Id;
Err_No : Node_Id;
Unit1 : Node_Id;
Unit2 : Node_Id;
function Entity_Of_Unit (U : Node_Id) return Entity_Id;
-- Return the appropriate entity for determining which unit
-- has a deeper scope: the defining entity for U, unless U
-- is a package instance, in which case we retrieve the
-- entity of the instance spec.
--------------------
-- Entity_Of_Unit --
--------------------
function Entity_Of_Unit (U : Node_Id) return Entity_Id is
begin
if Nkind (U) = N_Package_Instantiation
and then Analyzed (U)
then
return Defining_Entity (Instance_Spec (U));
else
return Defining_Entity (U);
end if;
end Entity_Of_Unit;
-- Start of processing for Use_Clause_Known
begin
-- If both current use type clause and the use type clause
-- for the type are at the compilation unit level, one of
-- the units must be an ancestor of the other, and the
-- warning belongs on the descendant.
if Nkind (Parent (Clause1)) = N_Compilation_Unit
and then
Nkind (Parent (Clause2)) = N_Compilation_Unit
then
-- If the unit is a subprogram body that acts as spec,
-- the context clause is shared with the constructed
-- subprogram spec. Clearly there is no redundancy.
if Clause1 = Clause2 then
return;
end if;
Unit1 := Unit (Parent (Clause1));
Unit2 := Unit (Parent (Clause2));
-- If both clauses are on same unit, or one is the body
-- of the other, or one of them is in a subunit, report
-- redundancy on the later one.
if Unit1 = Unit2 then
Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
Error_Msg_NE -- CODEFIX
("& is already use-visible through previous "
& "use_type_clause #??", Clause1, T);
return;
elsif Nkind (Unit1) = N_Subunit then
Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
Error_Msg_NE -- CODEFIX
("& is already use-visible through previous "
& "use_type_clause #??", Clause1, T);
return;
elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body)
and then Nkind (Unit1) /= Nkind (Unit2)
and then Nkind (Unit1) /= N_Subunit
then
Error_Msg_Sloc := Sloc (Clause1);
Error_Msg_NE -- CODEFIX
("& is already use-visible through previous "
& "use_type_clause #??", Current_Use_Clause (T), T);
return;
end if;
-- There is a redundant use type clause in a child unit.
-- Determine which of the units is more deeply nested.
-- If a unit is a package instance, retrieve the entity
-- and its scope from the instance spec.
Ent1 := Entity_Of_Unit (Unit1);
Ent2 := Entity_Of_Unit (Unit2);
if Scope (Ent2) = Standard_Standard then
Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
Err_No := Clause1;
elsif Scope (Ent1) = Standard_Standard then
Error_Msg_Sloc := Sloc (Id);
Err_No := Clause2;
-- If both units are child units, we determine which one
-- is the descendant by the scope distance to the
-- ultimate parent unit.
else
declare
S1, S2 : Entity_Id;
begin
S1 := Scope (Ent1);
S2 := Scope (Ent2);
while Present (S1)
and then Present (S2)
and then S1 /= Standard_Standard
and then S2 /= Standard_Standard
loop
S1 := Scope (S1);
S2 := Scope (S2);
end loop;
if S1 = Standard_Standard then
Error_Msg_Sloc := Sloc (Id);
Err_No := Clause2;
else
Error_Msg_Sloc := Sloc (Current_Use_Clause (T));
Err_No := Clause1;
end if;
end;
end if;
Error_Msg_NE -- CODEFIX
("& is already use-visible through previous "
& "use_type_clause #??", Err_No, Id);
-- Case where current use type clause and the use type
-- clause for the type are not both at the compilation unit
-- level. In this case we don't have location information.
else
Error_Msg_NE -- CODEFIX
("& is already use-visible through previous "
& "use type clause??", Id, T);
end if;
end Use_Clause_Known;
-- Here if Current_Use_Clause is not set for T, another case
-- where we do not have the location information available.
else
Error_Msg_NE -- CODEFIX
("& is already use-visible through previous "
& "use type clause??", Id, T);
end if;
-- The package where T is declared is already used
elsif In_Use (Scope (T)) then
Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T)));
Error_Msg_NE -- CODEFIX
("& is already use-visible through package use clause #??",
Id, T);
-- The current scope is the package where T is declared
else
Error_Msg_Node_2 := Scope (T);
Error_Msg_NE -- CODEFIX
("& is already use-visible inside package &??", Id, T);
end if;
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;
--------
-- ws --
--------
procedure ws 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 ws;
--------
-- we --
--------
procedure we (S : Entity_Id) is
E : Entity_Id;
begin
E := First_Entity (S);
while Present (E) loop
Write_Int (Int (E));
Write_Str (" === ");
Write_Name (Chars (E));
Write_Eol;
Next_Entity (E);
end loop;
end we;
end Sem_Ch8;