------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M . C H 8 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2005, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Util; use Exp_Util; with Fname; use Fname; with Freeze; use Freeze; with Lib; use Lib; with Lib.Load; use Lib.Load; with Lib.Xref; use Lib.Xref; with Namet; use Namet; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Output; use Output; with Restrict; use Restrict; with Rident; use Rident; with Rtsfind; use Rtsfind; with Sem; use Sem; 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_Disp; use Sem_Disp; with Sem_Res; use Sem_Res; with Sem_Util; use Sem_Util; with Sem_Type; use Sem_Type; with Stand; use Stand; with Sinfo; use Sinfo; with Sinfo.CN; use Sinfo.CN; with Snames; use Snames; with Style; use Style; with Table; with Tbuild; use Tbuild; with Uintp; use Uintp; with GNAT.Spelling_Checker; use GNAT.Spelling_Checker; package body Sem_Ch8 is ------------------------------------ -- Visibility and Name Resolution -- ------------------------------------ -- This package handles name resolution and the collection of -- interpretations for overloaded names, prior to overload resolution. -- Name resolution is the process that establishes a mapping between source -- identifiers and the entities they denote at each point in the program. -- Each entity is represented by a defining occurrence. Each identifier -- that denotes an entity points to the corresponding defining occurrence. -- This is the entity of the applied occurrence. Each occurrence holds -- an index into the names table, where source identifiers are stored. -- Each entry in the names table for an identifier or designator uses the -- Info pointer to hold a link to the currently visible entity that has -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id -- in package Sem_Util). The visibility is initialized at the beginning of -- semantic processing to make entities in package Standard immediately -- visible. The visibility table is used in a more subtle way when -- compiling subunits (see below). -- Entities that have the same name (i.e. homonyms) are chained. In the -- case of overloaded entities, this chain holds all the possible meanings -- of a given identifier. The process of overload resolution uses type -- information to select from this chain the unique meaning of a given -- identifier. -- Entities are also chained in their scope, through the Next_Entity link. -- As a consequence, the name space is organized as a sparse matrix, where -- each row corresponds to a scope, and each column to a source identifier. -- Open scopes, that is to say scopes currently being compiled, have their -- corresponding rows of entities in order, innermost scope first. -- The scopes of packages that are mentioned in context clauses appear in -- no particular order, interspersed among open scopes. This is because -- in the course of analyzing the context of a compilation, a package -- declaration is first an open scope, and subsequently an element of the -- context. If subunits or child units are present, a parent unit may -- appear under various guises at various times in the compilation. -- When the compilation of the innermost scope is complete, the entities -- defined therein are no longer visible. If the scope is not a package -- declaration, these entities are never visible subsequently, and can be -- removed from visibility chains. If the scope is a package declaration, -- its visible declarations may still be accessible. Therefore the entities -- defined in such a scope are left on the visibility chains, and only -- their visibility (immediately visibility or potential use-visibility) -- is affected. -- The ordering of homonyms on their chain does not necessarily follow -- the order of their corresponding scopes on the scope stack. For -- example, if package P and the enclosing scope both contain entities -- named E, then when compiling the package body the chain for E will -- hold the global entity first, and the local one (corresponding to -- the current inner scope) next. As a result, name resolution routines -- do not assume any relative ordering of the homonym chains, either -- for scope nesting or to order of appearance of context clauses. -- When compiling a child unit, entities in the parent scope are always -- immediately visible. When compiling the body of a child unit, private -- entities in the parent must also be made immediately visible. There -- are separate routines to make the visible and private declarations -- visible at various times (see package Sem_Ch7). -- +--------+ +-----+ -- | In use |-------->| EU1 |--------------------------> -- +--------+ +-----+ -- | | -- +--------+ +-----+ +-----+ -- | Stand. |---------------->| ES1 |--------------->| ES2 |---> -- +--------+ +-----+ +-----+ -- | | -- +---------+ | +-----+ -- | with'ed |------------------------------>| EW2 |---> -- +---------+ | +-----+ -- | | -- +--------+ +-----+ +-----+ -- | Scope2 |---------------->| E12 |--------------->| E22 |---> -- +--------+ +-----+ +-----+ -- | | -- +--------+ +-----+ +-----+ -- | Scope1 |---------------->| E11 |--------------->| E12 |---> -- +--------+ +-----+ +-----+ -- ^ | | -- | | | -- | +---------+ | | -- | | with'ed |-----------------------------------------> -- | +---------+ | | -- | | | -- Scope stack | | -- (innermost first) | | -- +----------------------------+ -- Names table => | Id1 | | | | Id2 | -- +----------------------------+ -- Name resolution must deal with several syntactic forms: simple names, -- qualified names, indexed names, and various forms of calls. -- Each identifier points to an entry in the names table. The resolution -- of a simple name consists in traversing the homonym chain, starting -- from the names table. If an entry is immediately visible, it is the one -- designated by the identifier. If only 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. 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 function. The renaming declaration N -- is rewritten as a function body that returns the attribute reference -- applied to the formals of the function. procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id); -- A renaming_as_body may occur after the entity of the original decla- -- ration has been frozen. In that case, the body of the new entity must -- be built now, because the usual mechanism of building the renamed -- body at the point of freezing will not work. Subp is the subprogram -- for which N provides the Renaming_As_Body. procedure Check_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 top scope table entry. function Has_Implicit_Character_Literal (N : Node_Id) return Boolean; -- Find a type derived from Character or Wide_Character in the prefix of N. -- Used to resolved qualified names whose selector is a character literal. function 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); -- Selected component is known to be expanded name. Verify legality -- of selector given the scope denoted by prefix. 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 (eg P."+"). -- A declarative part contains an implicit declaration of an operator -- if it has a declaration of a type to which one of the predefined -- operators apply. The existence of this routine is an artifact of -- our implementation: a more straightforward but more space-consuming -- choice would be to make all inherited operators explicit in the -- symbol table. procedure 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 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); -- Id is the subtype mark from a use type clause. This procedure makes -- the primitive operators of the type potentially use-visible. procedure Write_Info; -- Write debugging information on entities declared in current scope procedure Write_Scopes; pragma Warnings (Off, Write_Scopes); -- Debugging information: dump all entities on scope stack -------------------------------- -- Analyze_Exception_Renaming -- -------------------------------- -- The language only allows a single identifier, but the tree holds -- an identifier list. The parser has already issued an error message -- if there is more than one element in the list. procedure Analyze_Exception_Renaming (N : Node_Id) is Id : constant Node_Id := Defining_Identifier (N); Nam : constant Node_Id := Name (N); begin Enter_Name (Id); Analyze (Nam); Set_Ekind (Id, E_Exception); Set_Exception_Code (Id, Uint_0); Set_Etype (Id, Standard_Exception_Type); Set_Is_Pure (Id, Is_Pure (Current_Scope)); if not Is_Entity_Name (Nam) or else Ekind (Entity (Nam)) /= E_Exception then Error_Msg_N ("invalid exception name in renaming", Nam); else if Present (Renamed_Object (Entity (Nam))) then Set_Renamed_Object (Id, Renamed_Object (Entity (Nam))); else Set_Renamed_Object (Id, Entity (Nam)); end if; end if; end Analyze_Exception_Renaming; --------------------------- -- Analyze_Expanded_Name -- --------------------------- procedure Analyze_Expanded_Name (N : Node_Id) is begin -- If the entity pointer is already set, this is an internal node, or -- a node that is analyzed more than once, after a tree modification. -- In such a case there is no resolution to perform, just set the type. -- For completeness, analyze prefix as well. if Present (Entity (N)) then if Is_Type (Entity (N)) then Set_Etype (N, Entity (N)); else Set_Etype (N, Etype (Entity (N))); end if; Analyze (Prefix (N)); return; else Find_Expanded_Name (N); end if; end Analyze_Expanded_Name; --------------------------------------- -- Analyze_Generic_Function_Renaming -- --------------------------------------- procedure Analyze_Generic_Function_Renaming (N : Node_Id) is begin Analyze_Generic_Renaming (N, E_Generic_Function); end Analyze_Generic_Function_Renaming; -------------------------------------- -- Analyze_Generic_Package_Renaming -- -------------------------------------- procedure Analyze_Generic_Package_Renaming (N : Node_Id) is begin -- Apply the Text_IO Kludge here, since we may be renaming -- one of the subpackages of Text_IO, then join common routine. Text_IO_Kludge (Name (N)); Analyze_Generic_Renaming (N, E_Generic_Package); end Analyze_Generic_Package_Renaming; ---------------------------------------- -- Analyze_Generic_Procedure_Renaming -- ---------------------------------------- procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is begin Analyze_Generic_Renaming (N, E_Generic_Procedure); end Analyze_Generic_Procedure_Renaming; ------------------------------ -- Analyze_Generic_Renaming -- ------------------------------ procedure Analyze_Generic_Renaming (N : Node_Id; K : Entity_Kind) is New_P : 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; Generate_Definition (New_P); if Current_Scope /= Standard_Standard then Set_Is_Pure (New_P, Is_Pure (Current_Scope)); end if; if Nkind (Name (N)) = N_Selected_Component then Check_Generic_Child_Unit (Name (N), Inst); else Analyze (Name (N)); end if; if not Is_Entity_Name (Name (N)) then Error_Msg_N ("expect entity name in renaming declaration", Name (N)); Old_P := Any_Id; else Old_P := Entity (Name (N)); end if; Enter_Name (New_P); Set_Ekind (New_P, K); if Etype (Old_P) = Any_Type then null; elsif Ekind (Old_P) /= K then Error_Msg_N ("invalid generic unit name", Name (N)); else if Present (Renamed_Object (Old_P)) then Set_Renamed_Object (New_P, Renamed_Object (Old_P)); else Set_Renamed_Object (New_P, Old_P); end if; Set_Etype (New_P, Etype (Old_P)); Set_Has_Completion (New_P); if In_Open_Scopes (Old_P) then Error_Msg_N ("within its scope, generic denotes its instance", N); end if; Check_Library_Unit_Renaming (N, Old_P); end if; end Analyze_Generic_Renaming; ----------------------------- -- Analyze_Object_Renaming -- ----------------------------- procedure Analyze_Object_Renaming (N : Node_Id) is Id : constant Entity_Id := Defining_Identifier (N); Dec : Node_Id; Nam : constant Node_Id := Name (N); T : Entity_Id; T2 : Entity_Id; begin if Nam = Error then return; end if; Set_Is_Pure (Id, Is_Pure (Current_Scope)); Enter_Name (Id); -- The renaming of a component that depends on a discriminant -- requires an actual subtype, because in subsequent use of the object -- Gigi will be unable to locate the actual bounds. This explicit step -- is required when the renaming is generated in removing side effects -- of an already-analyzed expression. if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then T := Etype (Nam); Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam); if Present (Dec) then Insert_Action (N, Dec); T := Defining_Identifier (Dec); Set_Etype (Nam, T); end if; elsif Present (Subtype_Mark (N)) then Find_Type (Subtype_Mark (N)); T := Entity (Subtype_Mark (N)); Analyze_And_Resolve (Nam, T); -- 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_And_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 ('R'M 8.5.1(6))", N); elsif Null_Exclusion_Present (Access_Definition (N)) then Error_Msg_N ("(Ada 2005): null-excluding attribute ignored " & "('R'M 8.5.1(6))?", N); end if; end if; -- An object renaming requires an exact match of the type; -- class-wide matching is not allowed. if Is_Class_Wide_Type (T) and then Base_Type (Etype (Nam)) /= Base_Type (T) then Wrong_Type (Nam, T); end if; T2 := Etype (Nam); Set_Ekind (Id, E_Variable); Init_Size_Align (Id); if T = Any_Type or else Etype (Nam) = Any_Type then return; -- Verify that the renamed entity is an object or a function call. -- It may have been rewritten in several ways. elsif Is_Object_Reference (Nam) then if Comes_From_Source (N) and then Is_Dependent_Component_Of_Mutable_Object (Nam) then Error_Msg_N ("illegal renaming of discriminant-dependent component", Nam); else null; end if; -- A static function call may have been folded into a literal elsif Nkind (Original_Node (Nam)) = N_Function_Call -- When expansion is disabled, attribute reference is not -- rewritten as function call. Otherwise it may be rewritten -- as a conversion, so check original node. or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference and then Is_Function_Attribute_Name (Attribute_Name (Original_Node (Nam)))) -- Weird but legal, equivalent to renaming a function call or else (Is_Entity_Name (Nam) and then Ekind (Entity (Nam)) = E_Enumeration_Literal) or else (Nkind (Nam) = N_Type_Conversion and then Is_Tagged_Type (Entity (Subtype_Mark (Nam)))) then null; else if Nkind (Nam) = N_Type_Conversion then Error_Msg_N ("renaming of conversion only allowed for tagged types", Nam); else Error_Msg_N ("expect object name in renaming", Nam); end if; end if; Set_Etype (Id, T2); if not Is_Variable (Nam) then Set_Ekind (Id, E_Constant); Set_Never_Set_In_Source (Id, True); Set_Is_True_Constant (Id, True); end if; Set_Renamed_Object (Id, Nam); end Analyze_Object_Renaming; ------------------------------ -- Analyze_Package_Renaming -- ------------------------------ procedure Analyze_Package_Renaming (N : Node_Id) is New_P : constant Entity_Id := Defining_Entity (N); Old_P : Entity_Id; Spec : Node_Id; begin if Name (N) = Error then return; end if; -- Apply Text_IO kludge here, since we may be renaming one of -- the children of Text_IO Text_IO_Kludge (Name (N)); if Current_Scope /= Standard_Standard then Set_Is_Pure (New_P, Is_Pure (Current_Scope)); end if; Enter_Name (New_P); Analyze (Name (N)); if Is_Entity_Name (Name (N)) then Old_P := Entity (Name (N)); else Old_P := Any_Id; end if; if Etype (Old_P) = Any_Type then Error_Msg_N ("expect package name in renaming", Name (N)); -- Ada 2005 (AI-50217): Limited withed packages can not be renamed elsif Ekind (Old_P) = E_Package and then From_With_Type (Old_P) then Error_Msg_N ("limited withed package cannot be renamed", 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); else -- Entities in the old package are accessible through the -- renaming entity. The simplest implementation is to have -- both packages share the entity list. Set_Ekind (New_P, E_Package); Set_Etype (New_P, Standard_Void_Type); if Present (Renamed_Object (Old_P)) then Set_Renamed_Object (New_P, Renamed_Object (Old_P)); else Set_Renamed_Object (New_P, Old_P); end if; Set_Has_Completion (New_P); Set_First_Entity (New_P, First_Entity (Old_P)); Set_Last_Entity (New_P, Last_Entity (Old_P)); Set_First_Private_Entity (New_P, First_Private_Entity (Old_P)); Check_Library_Unit_Renaming (N, Old_P); Generate_Reference (Old_P, Name (N)); -- If this is the renaming declaration of a package instantiation -- within itself, it is the declaration that ends the list of actuals -- for the instantiation. At this point, the subtypes that rename -- the actuals are flagged as generic, to avoid spurious ambiguities -- if the actuals for two distinct formals happen to coincide. If -- the actual is a private type, the subtype has a private completion -- that is flagged in the same fashion. -- Resolution is identical to what is was in the original generic. -- On exit from the generic instance, these are turned into regular -- subtypes again, so they are compatible with types in their class. if not Is_Generic_Instance (Old_P) then return; else Spec := Specification (Unit_Declaration_Node (Old_P)); end if; if Nkind (Spec) = N_Package_Specification and then Present (Generic_Parent (Spec)) and then Old_P = Current_Scope and then Chars (New_P) = Chars (Generic_Parent (Spec)) then declare E : Entity_Id := First_Entity (Old_P); begin while Present (E) and then E /= New_P loop if Is_Type (E) and then Nkind (Parent (E)) = N_Subtype_Declaration then Set_Is_Generic_Actual_Type (E); if Is_Private_Type (E) and then Present (Full_View (E)) then Set_Is_Generic_Actual_Type (Full_View (E)); end if; end if; Next_Entity (E); end loop; end; end if; end if; end Analyze_Package_Renaming; ------------------------------- -- Analyze_Renamed_Character -- ------------------------------- procedure Analyze_Renamed_Character (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean) is C : constant Node_Id := Name (N); begin if Ekind (New_S) = E_Function then Resolve (C, Etype (New_S)); if Is_Body then Check_Frozen_Renaming (N, New_S); end if; else Error_Msg_N ("character literal can only be renamed as function", N); end if; end Analyze_Renamed_Character; --------------------------------- -- Analyze_Renamed_Dereference -- --------------------------------- procedure Analyze_Renamed_Dereference (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean) is Nam : constant Node_Id := Name (N); P : constant Node_Id := Prefix (Nam); Typ : Entity_Id; 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); Old_S : Entity_Id; begin if Entity (Sel) = Any_Id then -- Selector is undefined on prefix. Error emitted already Set_Has_Completion (New_S); return; end if; -- Otherwise, find renamed entity, and build body of New_S as a call -- to it. Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S); if Old_S = Any_Id then Error_Msg_N (" no subprogram or entry matches specification", N); else if Is_Body then Check_Subtype_Conformant (New_S, Old_S, N); Generate_Reference (New_S, Defining_Entity (N), 'b'); Style.Check_Identifier (Defining_Entity (N), New_S); end if; Inherit_Renamed_Profile (New_S, Old_S); end if; Set_Convention (New_S, Convention (Old_S)); Set_Has_Completion (New_S, Inside_A_Generic); if Is_Body then Check_Frozen_Renaming (N, New_S); end if; end Analyze_Renamed_Entry; ----------------------------------- -- Analyze_Renamed_Family_Member -- ----------------------------------- procedure Analyze_Renamed_Family_Member (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean) is Nam : 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_Subprogram_Renaming -- --------------------------------- procedure Analyze_Subprogram_Renaming (N : Node_Id) is Spec : constant Node_Id := Specification (N); Save_AV : constant Ada_Version_Type := Ada_Version; Nam : constant Node_Id := Name (N); New_S : Entity_Id; Old_S : Entity_Id := Empty; Rename_Spec : Entity_Id; Is_Actual : Boolean := False; Inst_Node : Node_Id := Empty; 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). ------------------------- -- 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; -- 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 Attribute_Renaming (N); return; 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 Present (Corresponding_Formal_Spec (N)) then Is_Actual := True; Inst_Node := Unit_Declaration_Node (Corresponding_Formal_Spec (N)); if Is_Entity_Name (Nam) and then Present (Entity (Nam)) and then not Comes_From_Source (Nam) and then not Is_Overloaded (Nam) then Old_S := Entity (Nam); New_S := Analyze_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 " & "('R'M 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); if Present (Rename_Spec) then -- Renaming_As_Body. Renaming declaration is the completion of -- the declaration of Rename_Spec. We will build an actual body -- for it at the freezing point. Set_Corresponding_Spec (N, Rename_Spec); Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S); -- The body is created when the entity is frozen. If the context -- is generic, freeze_all is not invoked, so we need to indicate -- that the entity has a completion. Set_Has_Completion (Rename_Spec, Inside_A_Generic); if Ada_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); -- Indicate that the entity in the declaration functions like -- the corresponding body, and is not a new entity. Set_Ekind (New_S, E_Subprogram_Body); New_S := Rename_Spec; else Generate_Definition (New_S); New_Overloaded_Entity (New_S); if Is_Entity_Name (Nam) and then Is_Intrinsic_Subprogram (Entity (Nam)) then null; else Check_Delayed_Subprogram (New_S); end if; end if; -- There is no need for elaboration checks on the new entity, which -- may be called before the next freezing point where the body will -- appear. 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 -- Renamed entity is an entry or protected subprogram. For those -- cases an explicit body is built (at the point of freezing of -- this entity) that contains a call to the renamed entity. Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec)); return; elsif Nkind (Nam) = N_Explicit_Dereference then -- Renamed entity is designated by access_to_subprogram expression. -- Must build body to encapsulate call, as in the entry case. Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec)); return; elsif Nkind (Nam) = N_Indexed_Component then Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec)); return; elsif Nkind (Nam) = N_Character_Literal then Analyze_Renamed_Character (N, New_S, Present (Rename_Spec)); return; elsif (not Is_Entity_Name (Nam) and then Nkind (Nam) /= N_Operator_Symbol) or else not Is_Overloadable (Entity (Nam)) then Error_Msg_N ("expect valid subprogram name in renaming", N); return; end if; -- Most common case: subprogram renames subprogram. No body is -- generated in this case, so we must indicate that the declaration -- is complete as is. if No (Rename_Spec) then Set_Has_Completion (New_S); end if; -- Find the renamed entity that matches the given specification. -- Disable Ada_83 because there is no requirement of full conformance -- between renamed entity and new entity, even though the same circuit -- is used. Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95); if No (Old_S) then Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual); end if; if Old_S /= Any_Id then if Is_Actual and then 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; -- 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); elsif Ekind (Old_S) /= E_Operator then Check_Mode_Conformant (New_S, Old_S); if Is_Actual and then Error_Posted (New_S) then Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S); end if; end if; if No (Rename_Spec) then -- The parameter profile of the new entity is that of the renamed -- entity: the subtypes given in the specification are irrelevant. Inherit_Renamed_Profile (New_S, Old_S); -- A call to the subprogram is transformed into a call to the -- renamed entity. This is transitive if the renamed entity is -- itself a renaming. if Present (Alias (Old_S)) then Set_Alias (New_S, Alias (Old_S)); else Set_Alias (New_S, Old_S); end if; -- Note that we do not set Is_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 (Corresponding_Formal_Spec (N)) 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 (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); -- In the case where 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 not Is_Actual and then (Old_S = New_S or else (Nkind (Nam) /= N_Expanded_Name and then Chars (Old_S) = Chars (New_S))) then Error_Msg_N ("subprogram cannot rename itself", N); end if; Set_Convention (New_S, Convention (Old_S)); Set_Is_Abstract (New_S, Is_Abstract (Old_S)); Check_Library_Unit_Renaming (N, Old_S); -- Pathological case: procedure renames entry in the scope of -- its task. Entry is given by simple name, but body must be built -- for procedure. Of course if called it will deadlock. if Ekind (Old_S) = E_Entry then Set_Has_Completion (New_S, False); Set_Alias (New_S, Empty); end if; if Is_Actual then Freeze_Before (N, Old_S); Set_Has_Delayed_Freeze (New_S, False); Freeze_Before (N, New_S); -- 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 (Old_S) and then not Is_Abstract (Corresponding_Formal_Spec (N)) then Error_Msg_N ("abstract subprogram not allowed as generic actual", Nam); end if; end if; else -- A common error is to assume that implicit operators for types -- are defined in Standard, or in the scope of a subtype. In those -- cases where the renamed entity is given with an expanded name, -- it is worth mentioning that operators for the type are not -- declared in the scope given by the prefix. if Nkind (Nam) = N_Expanded_Name and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol and then Scope (Entity (Nam)) = Standard_Standard then declare T : constant Entity_Id := Base_Type (Etype (First_Formal (New_S))); begin Error_Msg_Node_2 := Prefix (Nam); Error_Msg_NE ("operator for type& is not declared in&", Prefix (Nam), T); end; else Error_Msg_NE ("no visible subprogram matches the specification for&", Spec, New_S); end if; if Present (Candidate_Renaming) then declare F1 : Entity_Id; F2 : Entity_Id; begin F1 := First_Formal (Candidate_Renaming); F2 := First_Formal (New_S); while Present (F1) and then Present (F2) loop Next_Formal (F1); Next_Formal (F2); end loop; if Present (F1) and then Present (Default_Value (F1)) then if Present (Next_Formal (F1)) then Error_Msg_NE ("\missing specification for &" & " and other formals with defaults", Spec, F1); else Error_Msg_NE ("\missing specification for &", Spec, F1); end if; end if; end; end if; end if; Ada_Version := Save_AV; 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 Set_Hidden_By_Use_Clause (N, No_Elist); -- Use clause is not allowed in a spec of a predefined package -- declaration except that packages whose file name starts a-n -- are OK (these are children of Ada.Numerics, and such packages -- are never loaded by Rtsfind). if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit)) and then Name_Buffer (1 .. 3) /= "a-n" and then Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration then Error_Msg_N ("use clause not allowed in predefined spec", N); end if; -- Chain clause to list of use clauses in current scope if Nkind (Parent (N)) /= N_Compilation_Unit then Chain_Use_Clause (N); end if; -- Loop through package names to identify referenced packages Pack_Name := First (Names (N)); while Present (Pack_Name) loop Analyze (Pack_Name); if Nkind (Parent (N)) = N_Compilation_Unit and then Nkind (Pack_Name) = N_Expanded_Name then declare Pref : Node_Id := Prefix (Pack_Name); begin while Nkind (Pref) = N_Expanded_Name loop Pref := Prefix (Pref); end loop; if Entity (Pref) = Standard_Standard then Error_Msg_N ("predefined package Standard cannot appear" & " in a context clause", Pref); end if; end; end if; Next (Pack_Name); end loop; -- Loop through package names to mark all entities as potentially -- use visible. Pack_Name := First (Names (N)); while Present (Pack_Name) loop if Is_Entity_Name (Pack_Name) then Pack := Entity (Pack_Name); if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then if Ekind (Pack) = E_Generic_Package then Error_Msg_N ("a generic package is not allowed in a use clause", Pack_Name); else Error_Msg_N ("& is not a usable package", Pack_Name); end if; 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; end if; Next (Pack_Name); end loop; end Analyze_Use_Package; ---------------------- -- Analyze_Use_Type -- ---------------------- procedure Analyze_Use_Type (N : Node_Id) is Id : Entity_Id; begin Set_Hidden_By_Use_Clause (N, No_Elist); -- Chain clause to list of use clauses in current scope if Nkind (Parent (N)) /= N_Compilation_Unit then Chain_Use_Clause (N); end if; Id := First (Subtype_Marks (N)); while Present (Id) loop Find_Type (Id); if Entity (Id) /= Any_Type then Use_One_Type (Id); 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 (Entity (Id))) and then Scope (Entity (Id)) /= System_Aux_Id then Check_In_Previous_With_Clause (N, Prefix (Id)); end if; 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 return False; elsif In_Use (Pack) then Set_Redundant_Use (Pack_Name, True); return False; elsif Present (Renamed_Object (Pack)) and then In_Use (Renamed_Object (Pack)) then Set_Redundant_Use (Pack_Name, True); return False; else return True; end if; end Applicable_Use; ------------------------ -- Attribute_Renaming -- ------------------------ procedure Attribute_Renaming (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Nam : constant Node_Id := Name (N); Spec : constant Node_Id := Specification (N); New_S : constant Entity_Id := Defining_Unit_Name (Spec); Aname : constant Name_Id := Attribute_Name (Nam); Form_Num : Nat := 0; Expr_List : List_Id := No_List; Attr_Node : Node_Id; Body_Node : Node_Id; Param_Spec : Node_Id; begin Generate_Definition (New_S); -- This procedure is called in the context of subprogram renaming, -- and thus the attribute must be one that is a subprogram. All of -- those have at least one formal parameter, with the singular -- exception of AST_Entry (which is a real oddity, it is odd that -- this can be renamed at all!) if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then if Aname /= Name_AST_Entry then Error_Msg_N ("subprogram renaming an attribute must have formals", N); return; end if; else Param_Spec := First (Parameter_Specifications (Spec)); while Present (Param_Spec) loop Form_Num := Form_Num + 1; if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then Find_Type (Parameter_Type (Param_Spec)); -- The profile of the new entity denotes the base type (s) of -- the types given in the specification. For access parameters -- there are no subtypes involved. Rewrite (Parameter_Type (Param_Spec), New_Reference_To (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc)); end if; if No (Expr_List) then Expr_List := New_List; end if; Append_To (Expr_List, Make_Identifier (Loc, Chars => Chars (Defining_Identifier (Param_Spec)))); -- 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 numbers -- of number of types of parameters are detected when we analyze the -- body of the subprogram that we construct. if Form_Num > 2 then Error_Msg_N ("too many formals for attribute", N); -- 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 : Entity_Id; Decl : Node_Id; begin Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); Decl := Make_Object_Declaration (Loc, Defining_Identifier => Ent, Object_Definition => New_Occurrence_Of (RTE (RE_AST_Handler), Loc), Expression => Nam, Constant_Present => True); Set_Assignment_OK (Decl, True); Insert_Action (N, Decl); Attr_Node := Make_Identifier (Loc, Chars (Ent)); end; -- For all other attributes, we rewrite the attribute node to have -- a list of expressions corresponding to the subprogram formals. -- A renaming declaration is not a freeze point, and the analysis of -- the attribute reference should not freeze the type of the prefix. else Attr_Node := Make_Attribute_Reference (Loc, Prefix => Prefix (Nam), Attribute_Name => Aname, Expressions => Expr_List); Set_Must_Not_Freeze (Attr_Node); Set_Must_Not_Freeze (Prefix (Nam)); end if; -- Case of renaming a function if Nkind (Spec) = N_Function_Specification then if Is_Procedure_Attribute_Name (Aname) then Error_Msg_N ("attribute can only be renamed as procedure", Nam); return; end if; Find_Type (Subtype_Mark (Spec)); Rewrite (Subtype_Mark (Spec), New_Reference_To (Base_Type (Entity (Subtype_Mark (Spec))), Loc)); Body_Node := Make_Subprogram_Body (Loc, Specification => Spec, Declarations => New_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List ( Make_Return_Statement (Loc, Expression => Attr_Node)))); -- Case of renaming a procedure else if not Is_Procedure_Attribute_Name (Aname) then Error_Msg_N ("attribute can only be renamed as function", Nam); return; end if; Body_Node := Make_Subprogram_Body (Loc, Specification => Spec, Declarations => New_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List (Attr_Node))); end if; Rewrite (N, Body_Node); Analyze (N); if Is_Compilation_Unit (New_S) then Error_Msg_N ("a library unit can only rename another library unit", N); end if; Set_Etype (New_S, Base_Type (Etype (New_S))); -- We suppress elaboration warnings for the resulting entity, since -- clearly they are not needed, and more particularly, in the case -- of a generic formal subprogram, the resulting entity can appear -- after the instantiation itself, and thus look like a bogus case -- of access before elaboration. Set_Suppress_Elaboration_Warnings (New_S); end Attribute_Renaming; ---------------------- -- Chain_Use_Clause -- ---------------------- procedure Chain_Use_Clause (N : Node_Id) is begin Set_Next_Use_Clause (N, Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause); Scope_Stack.Table (Scope_Stack.Last).First_Use_Clause := N; end Chain_Use_Clause; --------------------------- -- Check_Frozen_Renaming -- --------------------------- procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is B_Node : Node_Id; Old_S : Entity_Id; begin if Is_Frozen (Subp) and then not Has_Completion (Subp) then B_Node := Build_Renamed_Body (Parent (Declaration_Node (Subp)), Defining_Entity (N)); if Is_Entity_Name (Name (N)) then Old_S := Entity (Name (N)); if not Is_Frozen (Old_S) 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; ----------------------------------- -- 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 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; elsif Scope (Old_E) /= Standard_Standard and then not Is_Child_Unit (Old_E) then Error_Msg_N ("renamed unit must be a library unit", Name (N)); -- 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 Ekind (Old_E) = E_Package or else Ekind (Old_E) = E_Generic_Package then -- Inherit categorization flags New_E := Defining_Entity (N); Set_Is_Pure (New_E, Is_Pure (Old_E)); Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E)); Set_Is_Remote_Call_Interface (New_E, Is_Remote_Call_Interface (Old_E)); Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E)); Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E)); end if; end Check_Library_Unit_Renaming; --------------- -- End_Scope -- --------------- procedure End_Scope is Id : Entity_Id; Prev : Entity_Id; Outer : Entity_Id; begin Id := First_Entity (Current_Scope); while Present (Id) loop -- An entity in the current scope is not necessarily the first one -- on its homonym chain. Find its predecessor if any, -- If it is an internal entity, it will not be in the visibility -- chain altogether, and there is nothing to unchain. if Id /= Current_Entity (Id) then Prev := Current_Entity (Id); while Present (Prev) and then Present (Homonym (Prev)) and then Homonym (Prev) /= Id loop Prev := Homonym (Prev); end loop; -- Skip to end of loop if Id is not in the visibility chain if No (Prev) or else Homonym (Prev) /= Id then goto Next_Ent; end if; else Prev := Empty; end if; Outer := Homonym (Id); Set_Is_Immediately_Visible (Id, False); while Present (Outer) and then Scope (Outer) = Current_Scope loop Outer := Homonym (Outer); end loop; -- Reset homonym link of other entities, but do not modify link -- between entities in current scope, so that the back-end can have -- a proper count of local overloadings. if No (Prev) then Set_Name_Entity_Id (Chars (Id), Outer); elsif Scope (Prev) /= Scope (Id) then Set_Homonym (Prev, Outer); end if; <> Next_Entity (Id); end loop; -- If the scope generated freeze actions, place them before the -- current declaration and analyze them. Type declarations and -- the bodies of initialization procedures can generate such nodes. -- We follow the parent chain until we reach a list node, which is -- the enclosing list of declarations. If the list appears within -- a protected definition, move freeze nodes outside the protected -- type altogether. if Present (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions) then declare Decl : Node_Id; L : constant List_Id := Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions; begin if Is_Itype (Current_Scope) then Decl := Associated_Node_For_Itype (Current_Scope); else Decl := Parent (Current_Scope); end if; Pop_Scope; while not (Is_List_Member (Decl)) or else Nkind (Parent (Decl)) = N_Protected_Definition or else Nkind (Parent (Decl)) = N_Task_Definition loop Decl := Parent (Decl); end loop; Insert_List_Before_And_Analyze (Decl, L); end; else Pop_Scope; end if; end End_Scope; --------------------- -- End_Use_Clauses -- --------------------- procedure End_Use_Clauses (Clause : Node_Id) is U : Node_Id; 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 (Op : Entity_Id; F : Entity_Id) return Boolean; -- Check whether Op is a primitive operator of a use-visible type --------------------------- -- Is_Primitive_Operator -- --------------------------- function Is_Primitive_Operator (Op : Entity_Id; F : Entity_Id) return Boolean is T : constant Entity_Id := Etype (F); begin return In_Use (T) and then Scope (T) = Scope (Op); end Is_Primitive_Operator; -- Start of processing for End_Use_Package begin Pack_Name := First (Names (N)); while Present (Pack_Name) loop Pack := Entity (Pack_Name); if Ekind (Pack) = E_Package then if In_Open_Scopes (Pack) then null; elsif not Redundant_Use (Pack_Name) then Set_In_Use (Pack, False); Id := First_Entity (Pack); while Present (Id) loop -- Preserve use-visibility of operators 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 (Id, First_Formal (Id)) or else (Present (Next_Formal (First_Formal (Id))) and then Is_Primitive_Operator (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); end if; if Chars (Pack) = Name_System and then Scope (Pack) = Standard_Standard and then Present_System_Aux then Id := First_Entity (System_Aux_Id); while Present (Id) loop Set_Is_Potentially_Use_Visible (Id, False); if Is_Private_Type (Id) and then Present (Full_View (Id)) then Set_Is_Potentially_Use_Visible (Full_View (Id), False); end if; Next_Entity (Id); end loop; Set_In_Use (System_Aux_Id, False); end if; else Set_Redundant_Use (Pack_Name, False); end if; end if; Next (Pack_Name); end loop; if Present (Hidden_By_Use_Clause (N)) then Elmt := First_Elmt (Hidden_By_Use_Clause (N)); while Present (Elmt) loop Set_Is_Immediately_Visible (Node (Elmt)); Next_Elmt (Elmt); end loop; Set_Hidden_By_Use_Clause (N, No_Elist); end if; end End_Use_Package; ------------------ -- End_Use_Type -- ------------------ procedure End_Use_Type (N : Node_Id) is Id : Entity_Id; Op_List : Elist_Id; Elmt : Elmt_Id; T : Entity_Id; begin Id := First (Subtype_Marks (N)); while Present (Id) loop -- 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 then null; -- Note that the use_Type clause may mention a subtype of the -- type whose primitive operations have been made visible. Here -- as elsewhere, it is the base type that matters for visibility. elsif In_Open_Scopes (Scope (Base_Type (T))) then null; elsif not Redundant_Use (Id) then Set_In_Use (T, False); Set_In_Use (Base_Type (T), False); Op_List := Collect_Primitive_Operations (T); Elmt := First_Elmt (Op_List); while Present (Elmt) loop if Nkind (Node (Elmt)) = N_Defining_Operator_Symbol then Set_Is_Potentially_Use_Visible (Node (Elmt), False); end if; Next_Elmt (Elmt); end loop; end if; <> Next (Id); end loop; end End_Use_Type; ---------------------- -- Find_Direct_Name -- ---------------------- procedure Find_Direct_Name (N : Node_Id) is E : Entity_Id; E2 : Entity_Id; Msg : Boolean; Inst : Entity_Id := Empty; -- Enclosing instance, if any Homonyms : Entity_Id; -- Saves start of homonym chain Nvis_Entity : Boolean; -- Set True to indicate that at there is at least one entity on the -- homonym chain which, while not visible, is visible enough from the -- user point of view to warrant an error message of "not visible" -- rather than undefined. 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 Known_But_Invisible (E : Entity_Id) return Boolean; -- This function determines whether the entity E (which is not -- visible) can reasonably be considered to be known to the writer -- of the reference. This is a heuristic test, used only for the -- purposes of figuring out whether we prefer to complain that an -- entity is undefined or invisible (and identify the declaration -- of the invisible entity in the latter case). The point here is -- that we don't want to complain that something is invisible and -- then point to something entirely mysterious to the writer. procedure Nvis_Messages; -- Called if there are no visible entries for N, but there is at least -- one non-directly visible, or hidden declaration. This procedure -- outputs an appropriate set of error messages. procedure Undefined (Nvis : Boolean); -- This function is called if the current node has no corresponding -- visible entity or entities. The value set in Msg indicates whether -- an error message was generated (multiple error messages for the -- same variable are generally suppressed, see body for details). -- Msg is True if an error message was generated, False if not. This -- value is used by the caller to determine whether or not to output -- additional messages where appropriate. The parameter is set False -- to get the message "X is undefined", and True to get the message -- "X is not visible". ------------------------- -- From_Actual_Package -- ------------------------- function From_Actual_Package (E : Entity_Id) return Boolean is Scop : constant Entity_Id := Scope (E); Act : Entity_Id; begin if not In_Instance then return False; else Inst := Current_Scope; while Present (Inst) and then Ekind (Inst) /= E_Package and then not Is_Generic_Instance (Inst) loop Inst := Scope (Inst); end loop; if No (Inst) then return False; end if; Act := First_Entity (Inst); while Present (Act) loop if Ekind (Act) = E_Package then -- Check for end of actuals list if Renamed_Object (Act) = Inst then return False; elsif Present (Associated_Formal_Package (Act)) and then Renamed_Object (Act) = Scop then -- Entity comes from (instance of) formal package return True; else Next_Entity (Act); end if; else Next_Entity (Act); end if; end loop; return False; end if; end From_Actual_Package; ------------------------- -- Known_But_Invisible -- ------------------------- function Known_But_Invisible (E : Entity_Id) return Boolean is Fname : File_Name_Type; begin -- Entities in Standard are always considered to be known if Sloc (E) <= Standard_Location then return True; -- An entity that does not come from source is always considered -- to be unknown, since it is an artifact of code expansion. elsif not Comes_From_Source (E) then return False; -- In gnat internal mode, we consider all entities known elsif GNAT_Mode then return True; end if; -- Here we have an entity that is not from package Standard, and -- which comes from Source. See if it comes from an internal file. Fname := Unit_File_Name (Get_Source_Unit (E)); -- Case of from internal file if Is_Internal_File_Name (Fname) then -- Private part entities in internal files are never considered -- to be known to the writer of normal application code. if Is_Hidden (E) then return False; end if; -- Entities from System packages other than System and -- System.Storage_Elements are not considered to be known. -- System.Auxxxx files are also considered known to the user. -- Should refine this at some point to generally distinguish -- between known and unknown internal files ??? Get_Name_String (Fname); return Name_Len < 2 or else Name_Buffer (1 .. 2) /= "s-" or else Name_Buffer (3 .. 8) = "stoele" or else Name_Buffer (3 .. 5) = "aux"; -- If not an internal file, then entity is definitely known, -- even if it is in a private part (the message generated will -- note that it is in a private part) else return True; end if; end Known_But_Invisible; ------------------- -- Nvis_Messages -- ------------------- procedure Nvis_Messages is Comp_Unit : Node_Id; Ent : Entity_Id; 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); Item := First (Context_Items (Comp_Unit)); Error_Msg_Sloc := No_Location; 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 ("multiple use clauses cause hiding!", N); Hidden := True; end if; Error_Msg_Sloc := Sloc (Ent); Error_Msg_N ("hidden declaration#!", N); end if; Ent := Homonym (Ent); end loop; -- If we found hidden declarations, then that's enough, don't -- bother looking for non-visible declarations as well. if Hidden then return; end if; -- Second loop does non-directly visible declarations Ent := Homonyms; while Present (Ent) loop if not Is_Potentially_Use_Visible (Ent) then -- Do not bother the user with unknown entities if not Known_But_Invisible (Ent) then goto Continue; end if; Error_Msg_Sloc := Sloc (Ent); -- Output message noting that there is a non-visible -- declaration, distinguishing the private part case. if Is_Hidden (Ent) then Error_Msg_N ("non-visible (private) declaration#!", N); else Error_Msg_N ("non-visible declaration#!", N); if Is_Compilation_Unit (Ent) and then Nkind (Parent (Parent (N))) = N_Use_Package_Clause then Error_Msg_NE ("\possibly missing with_clause for&", N, Ent); 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; <> 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 Get_Name_String (Chars (N)); declare Case_Str : constant String := Name_Buffer (1 .. Name_Len); Case_Stm : constant Node_Id := Parent (Parent (N)); Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm)); Lit : Node_Id; begin if Is_Enumeration_Type (Case_Typ) and then Case_Typ /= Standard_Character and then Case_Typ /= Standard_Wide_Character and then Case_Typ /= Standard_Wide_Wide_Character then Lit := First_Literal (Case_Typ); Get_Name_String (Chars (Lit)); if Chars (Lit) /= Chars (N) and then Is_Bad_Spelling_Of (Case_Str, Name_Buffer (1 .. Name_Len)) then Error_Msg_Node_2 := Lit; Error_Msg_N ("& is undefined, assume misspelling of &", N); Rewrite (N, New_Occurrence_Of (Lit, Sloc (N))); return; end if; Lit := Next_Literal (Lit); end if; end; end if; -- Normal processing Set_Entity (N, Any_Id); Set_Etype (N, Any_Type); -- We use the table Urefs to keep track of entities for which we -- have issued errors for undefined references. Multiple errors -- for a single name are normally suppressed, however we modify -- the error message to alert the programmer to this effect. for J in Urefs.First .. Urefs.Last loop if Chars (N) = Chars (Urefs.Table (J).Node) then if Urefs.Table (J).Err /= No_Error_Msg and then Sloc (N) /= Urefs.Table (J).Loc then Error_Msg_Node_1 := Urefs.Table (J).Node; if Urefs.Table (J).Nvis then Change_Error_Text (Urefs.Table (J).Err, "& is not visible (more references follow)"); else Change_Error_Text (Urefs.Table (J).Err, "& is undefined (more references follow)"); end if; Urefs.Table (J).Err := No_Error_Msg; end if; -- Although we will set Msg False, and thus suppress the -- message, we also set Error_Posted True, to avoid any -- cascaded messages resulting from the undefined reference. Msg := False; Set_Error_Posted (N, True); return; end if; end loop; -- If entry not found, this is first undefined occurrence if Nvis then Error_Msg_N ("& is not visible!", N); Emsg := Get_Msg_Id; else Error_Msg_N ("& is undefined!", N); Emsg := Get_Msg_Id; -- A very bizarre special check, if the undefined identifier -- is put or put_line, then add a special error message (since -- this is a very common error for beginners to make). if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then Error_Msg_N ("\possible missing with of 'Text_'I'O!", N); end if; -- Now check for possible misspellings Get_Name_String (Chars (N)); declare E : Entity_Id; Ematch : Entity_Id := Empty; Last_Name_Id : constant Name_Id := Name_Id (Nat (First_Name_Id) + Name_Entries_Count - 1); S : constant String (1 .. Name_Len) := Name_Buffer (1 .. Name_Len); begin for N in First_Name_Id .. Last_Name_Id loop E := Get_Name_Entity_Id (N); if Present (E) and then (Is_Immediately_Visible (E) or else Is_Potentially_Use_Visible (E)) then Get_Name_String (N); if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then Ematch := E; exit; end if; end if; end loop; if Present (Ematch) then Error_Msg_NE ("\possible misspelling of&", N, Ematch); end if; end; end if; -- Make entry in undefined references table unless the full -- errors switch is set, in which case by refraining from -- generating the table entry, we guarantee that we get an -- error message for every undefined reference. if not All_Errors_Mode then Urefs.Increment_Last; Urefs.Table (Urefs.Last).Node := N; Urefs.Table (Urefs.Last).Err := Emsg; Urefs.Table (Urefs.Last).Nvis := Nvis; Urefs.Table (Urefs.Last).Loc := Sloc (N); end if; Msg := True; end Undefined; -- Start of processing for Find_Direct_Name begin -- If the entity pointer is already set, this is an internal node, or -- a node that is analyzed more than once, after a tree modification. -- In such a case there is no resolution to perform, just set the type. if Present (Entity (N)) then if Is_Type (Entity (N)) then Set_Etype (N, Entity (N)); else declare Entyp : constant Entity_Id := Etype (Entity (N)); begin -- One special case here. If the Etype field is already set, -- and references the packed array type corresponding to the -- etype of the referenced entity, then leave it alone. This -- happens for trees generated from Exp_Pakd, where expressions -- can be deliberately "mis-typed" to the packed array type. if Is_Array_Type (Entyp) and then Is_Packed (Entyp) and then Present (Etype (N)) and then Etype (N) = Packed_Array_Type (Entyp) then null; -- If not that special case, then just reset the Etype else Set_Etype (N, Etype (Entity (N))); end if; end; end if; return; end if; -- Here if Entity pointer was not set, we need full visibility analysis -- First we generate debugging output if the debug E flag is set. if Debug_Flag_E then Write_Str ("Looking for "); Write_Name (Chars (N)); Write_Eol; end if; Homonyms := Current_Entity (N); Nvis_Entity := False; E := Homonyms; while Present (E) loop -- If entity is immediately visible or potentially use -- visible, then process the entity and we are done. if Is_Immediately_Visible (E) then goto Immediately_Visible_Entity; elsif Is_Potentially_Use_Visible (E) then goto Potentially_Use_Visible_Entity; -- Note if a known but invisible entity encountered elsif Known_But_Invisible (E) then Nvis_Entity := True; end if; -- Move to next entity in chain and continue search E := Homonym (E); end loop; -- If no entries on homonym chain that were potentially visible, -- and no entities reasonably considered as non-visible, then -- we have a plain undefined reference, with no additional -- explanation required! if not Nvis_Entity then Undefined (Nvis => False); -- 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)). <> 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 Beujolais effect -- that can occurr 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 Inst := Current_Scope; -- Find current instance 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; else Nvis_Messages; return; end if; end if; end; -- Come here with E set to the first immediately visible entity on -- the homonym chain. This is the one we want unless there is another -- immediately visible entity further on in the chain for a more -- inner scope (RM 8.3(8)). <> declare Level : Int; Scop : Entity_Id; begin -- Find scope level of initial entity. When compiling through -- Rtsfind, the previous context is not completely invisible, and -- an outer entity may appear on the chain, whose scope is below -- the entry for Standard that delimits the current scope stack. -- Indicate that the level for this spurious entry is outside of -- the current scope stack. Level := Scope_Stack.Last; loop Scop := Scope_Stack.Table (Level).Entity; exit when Scop = Scope (E); Level := Level - 1; exit when Scop = Standard_Standard; end loop; -- Now search remainder of homonym chain for more inner entry -- If the entity is Standard itself, it has no scope, and we -- compare it with the stack entry directly. E2 := Homonym (E); while Present (E2) loop if Is_Immediately_Visible (E2) then for J in Level + 1 .. Scope_Stack.Last loop if Scope_Stack.Table (J).Entity = Scope (E2) or else Scope_Stack.Table (J).Entity = E2 then Level := J; E := E2; exit; end if; end loop; end if; E2 := Homonym (E2); end loop; -- At the end of that loop, E is the innermost immediately -- visible entity, so we are all set. end; -- Come here with entity found, and stored in E <> begin if Comes_From_Source (N) and then Is_Remote_Access_To_Subprogram_Type (E) and then Expander_Active then Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N))); return; end if; Set_Entity (N, E); -- Why no Style_Check here??? if Is_Type (E) then Set_Etype (N, E); else Set_Etype (N, Get_Full_View (Etype (E))); end if; if Debug_Flag_E then Write_Str (" found "); Write_Entity_Info (E, " "); end if; -- If the Ekind of the entity is Void, it means that all homonyms -- are hidden from all visibility (RM 8.3(5,14-20)). However, this -- test is skipped if the current scope is a record and the name is -- a pragma argument expression (case of Atomic and Volatile pragmas -- and possibly other similar pragmas added later, which are allowed -- to reference components in the current record). if Ekind (E) = E_Void and then (not Is_Record_Type (Current_Scope) or else Nkind (Parent (N)) /= N_Pragma_Argument_Association) then Premature_Usage (N); -- If the entity is overloadable, collect all interpretations -- of the name for subsequent overload resolution. We optimize -- a bit here to do this only if we have an overloadable entity -- that is not on its own on the homonym chain. elsif Is_Overloadable (E) and then (Present (Homonym (E)) or else Current_Entity (N) /= E) then Collect_Interps (N); -- If no homonyms were visible, the entity is unambiguous if not Is_Overloaded (N) then Generate_Reference (E, N); end if; -- Case of non-overloadable entity, set the entity providing that -- we do not have the case of a discriminant reference within a -- default expression. Such references are replaced with the -- corresponding discriminal, which is the formal corresponding to -- to the discriminant in the initialization procedure. else -- Entity is unambiguous, indicate that it is referenced here -- One slightly odd case is that we do not want to set the -- Referenced flag if the entity is a label, and the identifier -- is the label in the source, since this is not a reference -- from the point of view of the user if Nkind (Parent (N)) = N_Label then declare R : constant Boolean := Referenced (E); begin Generate_Reference (E, N); Set_Referenced (E, R); end; -- Normal case, not a label. Generate reference else Generate_Reference (E, N); end if; -- Set Entity, with style check if need be. If this is a -- discriminant reference, it must be replaced by the -- corresponding discriminal, that is to say the parameter -- of the initialization procedure that corresponds to the -- discriminant. If this replacement is being performed, there -- is no style check to perform. -- This replacement must not be done if we are currently -- processing a generic spec or body, because the discriminal -- has not been not generated in this case. if not In_Default_Expression or else Ekind (E) /= E_Discriminant or else Inside_A_Generic then Set_Entity_With_Style_Check (N, E); -- The replacement is not done either for a task discriminant that -- appears in a default expression of an entry parameter. See -- Expand_Discriminant in exp_ch2 for details on their handling. elsif Is_Concurrent_Type (Scope (E)) then declare P : Node_Id := Parent (N); begin while Present (P) and then Nkind (P) /= N_Parameter_Specification and then Nkind (P) /= N_Component_Declaration loop P := Parent (P); end loop; if Present (P) and then Nkind (P) = N_Parameter_Specification then null; else Set_Entity (N, Discriminal (E)); end if; end; -- 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 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); while Present (Id) loop if Scope (Id) = P_Name then Candidate := Id; if Is_Child_Unit (Id) then exit when Is_Visible_Child_Unit (Id) or else Is_Immediately_Visible (Id); else exit when not Is_Hidden (Id) or else Is_Immediately_Visible (Id); end if; end if; Id := Homonym (Id); end loop; if No (Id) and then (Ekind (P_Name) = E_Procedure or else Ekind (P_Name) = E_Function) and then Is_Generic_Instance (P_Name) then -- Expanded name denotes entity in (instance of) generic subprogram. -- The entity may be in the subprogram instance, or may denote one of -- the formals, which is declared in the enclosing wrapper package. P_Name := Scope (P_Name); Id := Current_Entity (Selector); while Present (Id) loop exit when Scope (Id) = P_Name; Id := Homonym (Id); end loop; end if; if No (Id) or else Chars (Id) /= Chars (Selector) then Set_Etype (N, Any_Type); -- If we are looking for an entity defined in System, try to -- find it in the child package that may have been provided as -- an extension to System. The Extend_System pragma will have -- supplied the name of the extension, which may have to be loaded. if Chars (P_Name) = Name_System and then Scope (P_Name) = Standard_Standard and then Present (System_Extend_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 Is_Child_Unit (Candidate) then Error_Msg_N ("missing with_clause for child unit &", Selector); else Error_Msg_NE ("& is not a visible entity of&", N, Selector); end if; else -- Within the instantiation of a child unit, the prefix may -- denote the parent instance, but the selector has the -- name of the original child. Find whether we are within -- the corresponding instance, and get the proper entity, which -- can only be an enclosing scope. if O_Name /= P_Name and then In_Open_Scopes (P_Name) and then Is_Generic_Instance (P_Name) then declare S : Entity_Id := Current_Scope; P : Entity_Id; begin for J in reverse 0 .. Scope_Stack.Last loop S := Scope_Stack.Table (J).Entity; exit when S = Standard_Standard; if Ekind (S) = E_Function or else Ekind (S) = E_Package or else Ekind (S) = E_Procedure then P := Generic_Parent (Specification (Unit_Declaration_Node (S))); if Present (P) and then Chars (Scope (P)) = Chars (O_Name) and then Chars (P) = Chars (Selector) then Id := S; goto found; end if; end if; end loop; end; end if; if Chars (P_Name) = Name_Ada and then Scope (P_Name) = Standard_Standard then Error_Msg_Node_2 := Selector; Error_Msg_NE ("missing with for `&.&`", N, P_Name); -- If this is a selection from a dummy package, then -- suppress the error message, of course the entity -- is missing if the package is missing! elsif Sloc (Error_Msg_Node_2) = No_Location then null; -- Here we have the case of an undefined component else Error_Msg_NE ("& not declared in&", N, Selector); -- Check for misspelling of some entity in prefix Id := First_Entity (P_Name); Get_Name_String (Chars (Selector)); declare S : constant String (1 .. Name_Len) := Name_Buffer (1 .. Name_Len); begin while Present (Id) loop Get_Name_String (Chars (Id)); if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) and then not Is_Internal_Name (Chars (Id)) then Error_Msg_NE ("possible misspelling of&", Selector, Id); exit; end if; Next_Entity (Id); end loop; end; -- Specialize the message if this may be an instantiation -- of a child unit that was not mentioned in the context. if Nkind (Parent (N)) = N_Package_Instantiation and then Is_Generic_Instance (Entity (Prefix (N))) and then Is_Compilation_Unit (Generic_Parent (Parent (Entity (Prefix (N))))) then Error_Msg_NE ("\possible missing with clause on child unit&", N, Selector); end if; end if; end if; Id := Any_Id; end if; end if; <> if Comes_From_Source (N) and then Is_Remote_Access_To_Subprogram_Type (Id) then Id := Equivalent_Type (Id); Set_Chars (Selector, Chars (Id)); end if; -- 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 -- It is an entry call after all, either to the current task -- (which will deadlock) or to an enclosing task. Analyze_Selected_Component (N); return; end if; Change_Selected_Component_To_Expanded_Name (N); -- 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_With_Style_Check (N, Id); Generate_Reference (Id, N); end if; if Is_Type (Id) then Set_Etype (N, Id); else Set_Etype (N, Get_Full_View (Etype (Id))); end if; -- If the Ekind of the entity is Void, it means that all homonyms -- are hidden from all visibility (RM 8.3(5,14-20)). if Ekind (Id) = E_Void then Premature_Usage (N); elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then declare H : Entity_Id := Homonym (Id); begin while Present (H) loop if Scope (H) = Scope (Id) 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; 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 Within (Inner, Outer : Entity_Id) return Boolean; -- Determine whether a candidate subprogram is defined within -- the enclosing instance. If yes, it has precedence over outer -- candidates. function Is_Visible_Operation (Op : Entity_Id) return Boolean; -- If the renamed entity is an implicit operator, check whether it is -- visible because its operand type is properly visible. This -- check applies to explicit renamed entities that appear in the -- source in a renaming declaration or a formal subprogram instance, -- but not to default generic actuals with a name. ------------------------ -- Enclosing_Instance -- ------------------------ function Enclosing_Instance return Entity_Id is S : Entity_Id; begin if not Is_Generic_Instance (Current_Scope) and then not Is_Actual then return Empty; end if; S := Scope (Current_Scope); while S /= Standard_Standard loop if Is_Generic_Instance (S) then return S; end if; S := Scope (S); end loop; return Empty; end Enclosing_Instance; -------------------------- -- Is_Visible_Operation -- -------------------------- function Is_Visible_Operation (Op : Entity_Id) return Boolean is Scop : Entity_Id; Typ : Entity_Id; Btyp : Entity_Id; begin if Ekind (Op) /= E_Operator or else Scope (Op) /= Standard_Standard or else (In_Instance and then (not Is_Actual or else Present (Enclosing_Instance))) then return True; else -- For a fixed point type operator, check the resulting type, -- because it may be a mixed mode integer * fixed operation. if Present (Next_Formal (First_Formal (New_S))) and then Is_Fixed_Point_Type (Etype (New_S)) then Typ := Etype (New_S); else Typ := Etype (First_Formal (New_S)); end if; Btyp := Base_Type (Typ); if Nkind (Nam) /= N_Expanded_Name then return (In_Open_Scopes (Scope (Btyp)) or else Is_Potentially_Use_Visible (Btyp) or else In_Use (Btyp) or else In_Use (Scope (Btyp))); else Scop := Entity (Prefix (Nam)); if Ekind (Scop) = E_Package and then Present (Renamed_Object (Scop)) then Scop := Renamed_Object (Scop); end if; -- Operator is visible if prefix of expanded name denotes -- scope of type, or else type type is defined in System_Aux -- and the prefix denotes System. return Scope (Btyp) = Scop or else (Scope (Btyp) = System_Aux_Id and then Scope (Scope (Btyp)) = Scop); end if; end if; end Is_Visible_Operation; ------------ -- Within -- ------------ function Within (Inner, Outer : Entity_Id) return Boolean is Sc : Entity_Id := Scope (Inner); begin while Sc /= Standard_Standard loop if Sc = Outer then return True; else Sc := Scope (Sc); end if; end loop; return False; end Within; function Report_Overload return Entity_Id; -- List possible interpretations, and specialize message in the -- case of a generic actual. function Report_Overload return Entity_Id is begin if Is_Actual then Error_Msg_NE ("ambiguous actual subprogram&, " & "possible interpretations: ", N, Nam); else Error_Msg_N ("ambiguous subprogram, " & "possible interpretations: ", N); end if; List_Interps (Nam, N); return Old_S; end Report_Overload; -- Start of processing for Find_Renamed_Entry begin Old_S := Any_Id; Candidate_Renaming := Empty; if not Is_Overloaded (Nam) then if Entity_Matches_Spec (Entity (Nam), New_S) and then Is_Visible_Operation (Entity (Nam)) then Old_S := Entity (Nam); elsif Present (First_Formal (Entity (Nam))) and then Present (First_Formal (New_S)) and then (Base_Type (Etype (First_Formal (Entity (Nam)))) = Base_Type (Etype (First_Formal (New_S)))) then Candidate_Renaming := Entity (Nam); end if; else Get_First_Interp (Nam, 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 return (It.Nam); elsif Within (Old_S, Inst) then return (Old_S); else return Report_Overload; end if; 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); Set_Is_Overloaded (Nam, False); end if; return Old_S; end Find_Renamed_Entity; ----------------------------- -- Find_Selected_Component -- ----------------------------- procedure Find_Selected_Component (N : Node_Id) is P : 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; -- If the selector already has an entity, the node has been -- constructed in the course of expansion, and is known to be -- valid. Do not verify that it is defined for the type (it may -- be a private component used in the expansion of record equality). elsif Present (Entity (Selector_Name (N))) then if No (Etype (N)) or else Etype (N) = Any_Type then declare Sel_Name : 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 C_Etype := Build_Actual_Subtype_Of_Component ( Etype (Selector), N); else C_Etype := Empty; end if; if No (C_Etype) then C_Etype := Etype (Selector); else Insert_Action (N, C_Etype); C_Etype := Defining_Identifier (C_Etype); end if; Set_Etype (N, C_Etype); end; -- If this is the name of an entry or protected operation, and -- the prefix is an access type, insert an explicit dereference, -- so that entry calls are treated uniformly. if Is_Access_Type (Etype (P)) and then Is_Concurrent_Type (Designated_Type (Etype (P))) then declare New_P : 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. Analyze_Selected_Component (N); elsif Is_Appropriate_For_Entry_Prefix (P_Type) and then not In_Open_Scopes (P_Name) and then (not Is_Concurrent_Type (Etype (P_Name)) or else not In_Open_Scopes (Etype (P_Name))) then -- Call to protected operation or entry. Type checking is -- needed on the prefix. Analyze_Selected_Component (N); elsif (In_Open_Scopes (P_Name) and then Ekind (P_Name) /= E_Void and then not Is_Overloadable (P_Name)) or else (Is_Concurrent_Type (Etype (P_Name)) and then In_Open_Scopes (Etype (P_Name))) then -- Prefix denotes an enclosing loop, block, or task, i.e. an -- enclosing construct that is not a subprogram or accept. Find_Expanded_Name (N); elsif Ekind (P_Name) = E_Package then Find_Expanded_Name (N); elsif Is_Overloadable (P_Name) then -- The subprogram may be a renaming (of an enclosing scope) as -- in the case of the name of the generic within an instantiation. if (Ekind (P_Name) = E_Procedure or else Ekind (P_Name) = E_Function) and then Present (Alias (P_Name)) and then Is_Generic_Instance (Alias (P_Name)) then P_Name := Alias (P_Name); end if; if Is_Overloaded (P) then -- The prefix must resolve to a unique enclosing construct declare Found : Boolean := False; 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 a -- procedure or entry, as is P.X; this is an error. if Ekind (P_Name) /= E_Function and then (not Is_Overloaded (P) or else Nkind (Parent (N)) = N_Procedure_Call_Statement) then -- Prefix may mention a package that is hidden by a local -- declaration: let the user know. Scan the full homonym -- chain, the candidate package may be anywhere on it. if Present (Homonym (Current_Entity (P_Name))) then P_Name := Current_Entity (P_Name); while Present (P_Name) loop exit when Ekind (P_Name) = E_Package; P_Name := Homonym (P_Name); end loop; if Present (P_Name) then Error_Msg_Sloc := Sloc (Entity (Prefix (N))); Error_Msg_NE ("package& is hidden by declaration#", N, P_Name); Set_Entity (Prefix (N), P_Name); Find_Expanded_Name (N); return; else P_Name := Entity (Prefix (N)); end if; end if; Error_Msg_NE ("invalid prefix in selected component&", N, P_Name); Change_Selected_Component_To_Expanded_Name (N); Set_Entity (N, Any_Id); Set_Etype (N, Any_Type); else Nam := New_Copy (P); Save_Interps (P, Nam); Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam)); Analyze_Call (P); Analyze_Selected_Component (N); end if; end if; -- Remaining cases generate various error messages else -- Format node as expanded name, to avoid cascaded errors Change_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 " & "('R'M 3.10.1)", P); end if; else Error_Msg_N ( "invalid prefix in selected component", P); end if; end if; else -- If prefix is not the name of an entity, it must be an expression, -- whose type is appropriate for a record. This is determined by -- type resolution. Analyze_Selected_Component (N); end if; end Find_Selected_Component; --------------- -- Find_Type -- --------------- procedure Find_Type (N : Node_Id) is C : Entity_Id; Typ : Entity_Id; T : Entity_Id; T_Name : Entity_Id; begin if N = Error then return; elsif Nkind (N) = N_Attribute_Reference then -- Class attribute. This is only valid in Ada 95 mode, but we don't -- do a check, since the tagged type referenced could only exist if -- we were in 95 mode when it was declared (or, if we were in Ada -- 83 mode, then an error message would already have been issued). if Attribute_Name (N) = Name_Class then Check_Restriction (No_Dispatch, N); Find_Type (Prefix (N)); -- Propagate error from bad prefix if Etype (Prefix (N)) = Any_Type then Set_Entity (N, Any_Type); Set_Etype (N, Any_Type); return; end if; T := Base_Type (Entity (Prefix (N))); -- Case of non-tagged type if not Is_Tagged_Type (T) then if Ekind (T) = E_Incomplete_Type then -- It is legal to denote the class type of an incomplete -- type. The full type will have to be tagged, of course. Set_Is_Tagged_Type (T); Make_Class_Wide_Type (T); Set_Entity (N, Class_Wide_Type (T)); Set_Etype (N, Class_Wide_Type (T)); elsif Ekind (T) = E_Private_Type and then not Is_Generic_Type (T) and then In_Private_Part (Scope (T)) then -- The Class attribute can be applied to an untagged -- private type fulfilled by a tagged type prior to -- the full type declaration (but only within the -- parent package's private part). Create the class-wide -- type now and check that the full type is tagged -- later during its analysis. Note that we do not -- mark the private type as tagged, unlike the case -- of incomplete types, because the type must still -- appear untagged to outside units. if not Present (Class_Wide_Type (T)) then Make_Class_Wide_Type (T); end if; Set_Entity (N, Class_Wide_Type (T)); Set_Etype (N, Class_Wide_Type (T)); else -- Should we introduce a type Any_Tagged and use -- Wrong_Type here, it would be a bit more consistent??? Error_Msg_NE ("tagged type required, found}", Prefix (N), First_Subtype (T)); Set_Entity (N, Any_Type); return; end if; -- Case of tagged type else C := Class_Wide_Type (Entity (Prefix (N))); Set_Entity_With_Style_Check (N, C); Generate_Reference (C, N); Set_Etype (N, C); end if; -- Base attribute, not allowed in Ada 83 elsif Attribute_Name (N) = Name_Base then 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 Sloc (Typ) = Standard_Location and then Base_Type (Typ) = Typ and then Warn_On_Redundant_Constructs then Error_Msg_NE ("?redudant attribute, & is its own base type", N, Typ); end if; T := Base_Type (Typ); -- 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 (Entity (N)), Prefix => New_Copy (Prefix (Prefix (N))), Selector_Name => New_Reference_To (Entity (N), Sloc (N)))); else Rewrite (N, New_Reference_To (Entity (N), Sloc (N))); end if; Set_Entity (N, T); Set_Etype (N, T); end if; -- All other attributes are invalid in a subtype mark else Error_Msg_N ("invalid attribute in subtype mark", N); end if; else Analyze (N); if Is_Entity_Name (N) then T_Name := Entity (N); else Error_Msg_N ("subtype mark required in this context", N); Set_Etype (N, Any_Type); return; end if; if T_Name = Any_Id or else Etype (N) = Any_Type then -- Undefined id. Make it into a valid type Set_Entity (N, Any_Type); elsif not Is_Type (T_Name) and then T_Name /= Standard_Void_Type then Error_Msg_Sloc := Sloc (T_Name); Error_Msg_N ("subtype mark required in this context", N); Error_Msg_NE ("\found & declared#", N, T_Name); Set_Entity (N, Any_Type); else T_Name := Get_Full_View (T_Name); if In_Open_Scopes (T_Name) then if Ekind (Base_Type (T_Name)) = E_Task_Type then Error_Msg_N ("task type cannot be used as type mark " & "within its own body", N); else Error_Msg_N ("type declaration cannot refer to itself", N); end if; Set_Etype (N, Any_Type); Set_Entity (N, Any_Type); Set_Error_Posted (T_Name); return; end if; Set_Entity (N, T_Name); Set_Etype (N, T_Name); end if; end if; if Present (Etype (N)) 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; ------------------- -- Get_Full_View -- ------------------- function Get_Full_View (T_Name : Entity_Id) return Entity_Id is begin if Ekind (T_Name) = E_Incomplete_Type and then Present (Full_View (T_Name)) then return Full_View (T_Name); elsif Is_Class_Wide_Type (T_Name) and then Ekind (Root_Type (T_Name)) = E_Incomplete_Type and then Present (Full_View (Root_Type (T_Name))) then return Class_Wide_Type (Full_View (Root_Type (T_Name))); else return T_Name; end if; end Get_Full_View; ------------------------------------ -- Has_Implicit_Character_Literal -- ------------------------------------ function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is Id : Entity_Id; Found : Boolean := False; P : constant Entity_Id := Entity (Prefix (N)); Priv_Id : Entity_Id := Empty; begin if Ekind (P) = E_Package and then not In_Open_Scopes (P) then Priv_Id := First_Private_Entity (P); end if; if P = Standard_Standard then Change_Selected_Component_To_Expanded_Name (N); Rewrite (N, Selector_Name (N)); Analyze (N); Set_Etype (Original_Node (N), Standard_Character); return True; end if; Id := First_Entity (P); while Present (Id) and then Id /= Priv_Id loop if Is_Character_Type (Id) and then (Root_Type (Id) = Standard_Character or else Root_Type (Id) = Standard_Wide_Character or else Root_Type (Id) = Standard_Wide_Wide_Character) and then Id = Base_Type (Id) then -- We replace the node with the literal itself, resolve as a -- character, and set the type correctly. if not Found then Change_Selected_Component_To_Expanded_Name (N); Rewrite (N, Selector_Name (N)); Analyze (N); Set_Etype (N, Id); Set_Etype (Original_Node (N), Id); Found := True; else -- More than one type derived from Character in given scope. -- Collect all possible interpretations. Add_One_Interp (N, Id, Id); end if; end if; Next_Entity (Id); end loop; return Found; end Has_Implicit_Character_Literal; ---------------------- -- Has_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; Add_One_Interp (N, Predef_Op, T); -- For operators with unary and binary interpretations, add both if Present (Homonym (Predef_Op)) then Add_One_Interp (N, Homonym (Predef_Op), T); end if; -- 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 Id = Base_Type (Id) then Add_Implicit_Operator (Id); return True; end if; Next_Entity (Id); end loop; -- Equality: look for any non-limited type (result is Boolean) when Name_Op_Eq | Name_Op_Ne => while Id /= Priv_Id loop if Is_Type (Id) and then not Is_Limited_Type (Id) and then Id = Base_Type (Id) then Add_Implicit_Operator (Standard_Boolean, 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 Id = 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 Id = Base_Type (Id) then Add_Implicit_Operator (Id); return True; end if; Next_Entity (Id); end loop; -- Concatenation: any one-dimensional array type when Name_Op_Concat => while Id /= Priv_Id loop if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1 and then Id = Base_Type (Id) then Add_Implicit_Operator (Id); return True; end if; Next_Entity (Id); end loop; -- What is the others condition here? Should we be using a -- subtype of Name_Id that would restrict to operators ??? when others => null; end case; -- If we fall through, then we do not have an implicit operator return False; end Has_Implicit_Operator; -------------------- -- In_Open_Scopes -- -------------------- function In_Open_Scopes (S : Entity_Id) return Boolean is begin -- Since there are several scope stacks maintained by Scope_Stack each -- delineated by Standard (see comments by definition of Scope_Stack) -- it is necessary to end the search when Standard is reached. for J in reverse 0 .. Scope_Stack.Last loop if Scope_Stack.Table (J).Entity = S then return True; end if; -- We need Is_Active_Stack_Base to tell us when to stop rather -- than checking for Standard_Standard because there are cases -- where Standard_Standard appears in the middle of the active -- set of scopes. This affects the declaration and overriding -- of private inherited operations in instantiations of generic -- child units. exit when Scope_Stack.Table (J).Is_Active_Stack_Base; end loop; return False; end In_Open_Scopes; ----------------------------- -- Inherit_Renamed_Profile -- ----------------------------- procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is New_F : Entity_Id; Old_F : Entity_Id; Old_T : Entity_Id; New_T : Entity_Id; begin if Ekind (Old_S) = E_Operator then New_F := First_Formal (New_S); while Present (New_F) loop Set_Etype (New_F, Base_Type (Etype (New_F))); Next_Formal (New_F); end loop; Set_Etype (New_S, Base_Type (Etype (New_S))); else New_F := First_Formal (New_S); Old_F := First_Formal (Old_S); while Present (New_F) loop New_T := Etype (New_F); Old_T := Etype (Old_F); -- If the new type is a renaming of the old one, as is the -- case for actuals in instances, retain its name, to simplify -- later disambiguation. if Nkind (Parent (New_T)) = N_Subtype_Declaration and then Is_Entity_Name (Subtype_Indication (Parent (New_T))) and then Entity (Subtype_Indication (Parent (New_T))) = Old_T then null; else Set_Etype (New_F, Old_T); end if; Next_Formal (New_F); Next_Formal (Old_F); end loop; if Ekind (Old_S) = E_Function or else Ekind (Old_S) = E_Enumeration_Literal then Set_Etype (New_S, Etype (Old_S)); end if; end if; end Inherit_Renamed_Profile; ---------------- -- Initialize -- ---------------- procedure Initialize is begin Urefs.Init; end Initialize; ------------------------- -- Install_Use_Clauses -- ------------------------- procedure Install_Use_Clauses (Clause : Node_Id; Force_Installation : Boolean := False) is U : Node_Id := Clause; P : Node_Id; Id : Entity_Id; begin while Present (U) loop -- Case of USE package if Nkind (U) = N_Use_Package_Clause then P := First (Names (U)); while Present (P) loop Id := Entity (P); if Ekind (Id) = E_Package then if In_Use (Id) then Set_Redundant_Use (P, True); elsif Present (Renamed_Object (Id)) and then In_Use (Renamed_Object (Id)) then Set_Redundant_Use (P, True); 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). function Has_Components (T1 : Entity_Id) return Boolean is begin return Is_Record_Type (T1) or else (Is_Private_Type (T1) and then Has_Discriminants (T1)) or else (Is_Task_Type (T1) and then Has_Discriminants (T1)); end Has_Components; -- Start of processing for Is_Appropriate_For_Record begin return Present (T) and then (Has_Components (T) or else (Is_Access_Type (T) and then Has_Components (Designated_Type (T)))); end Is_Appropriate_For_Record; --------------- -- New_Scope -- --------------- procedure New_Scope (S : Entity_Id) is E : Entity_Id; begin if Ekind (S) = E_Void then null; -- Set scope depth if not a non-concurrent type, and we have not -- yet set the scope depth. This means that we have the first -- occurrence of the scope, and this is where the depth is set. elsif (not Is_Type (S) or else Is_Concurrent_Type (S)) and then not Scope_Depth_Set (S) then if S = Standard_Standard then Set_Scope_Depth_Value (S, Uint_0); elsif Is_Child_Unit (S) then Set_Scope_Depth_Value (S, Uint_1); elsif not Is_Record_Type (Current_Scope) then if Ekind (S) = E_Loop then Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope)); else Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1); end if; end if; end if; Scope_Stack.Increment_Last; 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_Entity_Suppress := Local_Entity_Suppress.Last; 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; 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; -- Copy from Scope (S) the categorization flags to S, this is not -- done in case Scope (S) is Standard_Standard since propagation -- is from library unit entity inwards. if S /= Standard_Standard and then Scope (S) /= Standard_Standard and then not Is_Child_Unit (S) then E := Scope (S); if Nkind (E) not in N_Entity then return; end if; -- We only propagate inwards for library level entities, -- inner level subprograms do not inherit the categorization. if Is_Library_Level_Entity (S) then Set_Is_Preelaborated (S, Is_Preelaborated (E)); Set_Is_Shared_Passive (S, Is_Shared_Passive (E)); Set_Categorization_From_Scope (E => S, Scop => E); end if; end if; end New_Scope; --------------- -- Pop_Scope -- --------------- procedure Pop_Scope is SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last); begin if Debug_Flag_E then Write_Info; end if; Scope_Suppress := SST.Save_Scope_Suppress; Local_Entity_Suppress.Set_Last (SST.Save_Local_Entity_Suppress); 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 return; end if; -- Free last subprogram name if allocated, and pop scope Free (SST.Last_Subprogram_Name); Scope_Stack.Decrement_Last; end Pop_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); else Error_Msg_N ("object& cannot be used before end of its declaration!", N); end if; end Premature_Usage; ------------------------ -- Present_System_Aux -- ------------------------ function Present_System_Aux (N : Node_Id := Empty) return Boolean is Loc : Source_Ptr; Aux_Name : Name_Id; Unum : Unit_Number_Type; Withn : Node_Id; With_Sys : Node_Id; The_Unit : Node_Id; function Find_System (C_Unit : Node_Id) return Entity_Id; -- Scan context clause of compilation unit to find a with_clause -- for System. ----------------- -- 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 Set_Is_Immediately_Visible (E, Is_Visible_Child_Unit (E) or else In_Open_Scopes (E)); else Set_Is_Immediately_Visible (E, True); end if; Next_Entity (E); if not Full_Vis then exit when E = First_Private_Entity (S); end if; end loop; -- The visibility of child units (siblings of current compilation) -- must be restored in any case. Their declarations may appear -- after the private part of the parent. if not Full_Vis and then Present (E) then while Present (E) loop if Is_Child_Unit (E) then Set_Is_Immediately_Visible (E, Is_Visible_Child_Unit (E) or else In_Open_Scopes (E)); end if; Next_Entity (E); end loop; end if; end if; if Is_Child_Unit (S) and not In_Child -- check only for current unit. then In_Child := True; -- restore visibility of parents according to whether the child -- is private and whether we are in its visible part. Comp_Unit := Parent (Unit_Declaration_Node (S)); if Nkind (Comp_Unit) = N_Compilation_Unit and then Private_Present (Comp_Unit) then Full_Vis := True; elsif (Ekind (S) = E_Package or else Ekind (S) = E_Generic_Package) and then (In_Private_Part (S) or else In_Package_Body (S)) then Full_Vis := True; elsif (Ekind (S) = E_Procedure or else Ekind (S) = E_Function) and then Has_Completion (S) then Full_Vis := True; else Full_Vis := False; end if; else Full_Vis := True; end if; end loop; 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); -- 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)); 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. -- 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 Set_Is_Potentially_Use_Visible (Id); Set_Is_Immediately_Visible (Prev, False); Append_Elmt (Prev, Hidden_By_Use_Clause (N)); end if; -- A user-defined operator is not use-visible if the -- predefined operator for the type is immediately visible, -- which is the case if the type of the operand is in an open -- scope. This does not apply to user-defined operators that -- have operands of different types, because the predefined -- mixed mode operations (multiplication and division) apply to -- universal types and do not hide anything. elsif Ekind (Prev) = E_Operator and then Operator_Matches_Spec (Prev, Id) and then In_Open_Scopes (Scope (Base_Type (Etype (First_Formal (Id))))) and then (No (Next_Formal (First_Formal (Id))) or else Etype (First_Formal (Id)) = Etype (Next_Formal (First_Formal (Id))) or else Chars (Prev) = Name_Op_Expon) then goto Next_Usable_Entity; end if; Prev := Homonym (Prev); end loop; -- On exit, we know entity is not hidden, unless it is private if not Is_Hidden (Id) and then ((not Is_Child_Unit (Id)) or else Is_Visible_Child_Unit (Id)) then Set_Is_Potentially_Use_Visible (Id); if Is_Private_Type (Id) and then Present (Full_View (Id)) then Set_Is_Potentially_Use_Visible (Full_View (Id)); end if; end if; <> Next_Entity (Id); end loop; -- Child units are also made use-visible by a use clause, but they -- may appear after all visible declarations in the parent entity list. while Present (Id) loop if Is_Child_Unit (Id) and then Is_Visible_Child_Unit (Id) then Set_Is_Potentially_Use_Visible (Id); end if; Next_Entity (Id); end loop; if Chars (Real_P) = Name_System and then Scope (Real_P) = Standard_Standard and then Present_System_Aux (N) then Use_One_Package (System_Aux_Id, N); end if; end Use_One_Package; ------------------ -- Use_One_Type -- ------------------ procedure Use_One_Type (Id : Node_Id) is T : Entity_Id; Op_List : Elist_Id; Elmt : Elmt_Id; begin -- It is the type determined by the subtype mark (8.4(8)) whose -- operations become potentially use-visible. T := Base_Type (Entity (Id)); Set_Redundant_Use (Id, In_Use (T) or else Is_Potentially_Use_Visible (T) or else In_Use (Scope (T))); if In_Open_Scopes (Scope (T)) then null; -- 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); Op_List := Collect_Primitive_Operations (T); Elmt := First_Elmt (Op_List); while Present (Elmt) loop if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol or else Chars (Node (Elmt)) in Any_Operator_Name) and then not Is_Hidden (Node (Elmt)) then Set_Is_Potentially_Use_Visible (Node (Elmt)); end if; Next_Elmt (Elmt); end loop; end if; end Use_One_Type; ---------------- -- Write_Info -- ---------------- procedure Write_Info is Id : Entity_Id := First_Entity (Current_Scope); begin -- No point in dumping standard entities if Current_Scope = Standard_Standard then return; end if; Write_Str ("========================================================"); Write_Eol; Write_Str (" Defined Entities in "); Write_Name (Chars (Current_Scope)); Write_Eol; Write_Str ("========================================================"); Write_Eol; if No (Id) then Write_Str ("-- none --"); Write_Eol; else while Present (Id) loop Write_Entity_Info (Id, " "); Next_Entity (Id); end loop; end if; if Scope (Current_Scope) = Standard_Standard then -- Print information on the current unit itself Write_Entity_Info (Current_Scope, " "); end if; Write_Eol; end Write_Info; ----------------- -- Write_Scopes -- ----------------- procedure Write_Scopes is S : Entity_Id; begin for J in reverse 1 .. Scope_Stack.Last loop S := Scope_Stack.Table (J).Entity; Write_Int (Int (S)); Write_Str (" === "); Write_Name (Chars (S)); Write_Eol; end loop; end Write_Scopes; end Sem_Ch8;