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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M . C H 8 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2012, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Tss; use Exp_Tss; with Exp_Util; use Exp_Util; with Fname; use Fname; with Freeze; use Freeze; with Impunit; use Impunit; with Lib; use Lib; with Lib.Load; use Lib.Load; with Lib.Xref; use Lib.Xref; with Namet; use Namet; with Namet.Sp; use Namet.Sp; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Output; use Output; with Restrict; use Restrict; with Rident; use Rident; with Rtsfind; use Rtsfind; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Cat; use Sem_Cat; with Sem_Ch3; use Sem_Ch3; with Sem_Ch4; use Sem_Ch4; with Sem_Ch6; use Sem_Ch6; with Sem_Ch12; use Sem_Ch12; with Sem_Ch13; use Sem_Ch13; with Sem_Dim; use Sem_Dim; with Sem_Disp; use Sem_Disp; with Sem_Dist; use Sem_Dist; with Sem_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; with Sem_Util; use Sem_Util; with Sem_Type; use Sem_Type; with Stand; use Stand; with Sinfo; use Sinfo; with Sinfo.CN; use Sinfo.CN; with Snames; use Snames; with Style; use Style; with Table; with Targparm; use Targparm; with Tbuild; use Tbuild; with Uintp; use Uintp; package body Sem_Ch8 is ------------------------------------ -- Visibility and Name Resolution -- ------------------------------------ -- This package handles name resolution and the collection of possible -- interpretations for overloaded names, prior to overload resolution. -- Name resolution is the process that establishes a mapping between source -- identifiers and the entities they denote at each point in the program. -- Each entity is represented by a defining occurrence. Each identifier -- that denotes an entity points to the corresponding defining occurrence. -- This is the entity of the applied occurrence. Each occurrence holds -- an index into the names table, where source identifiers are stored. -- Each entry in the names table for an identifier or designator uses the -- Info pointer to hold a link to the currently visible entity that has -- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id -- in package Sem_Util). The visibility is initialized at the beginning of -- semantic processing to make entities in package Standard immediately -- visible. The visibility table is used in a more subtle way when -- compiling subunits (see below). -- Entities that have the same name (i.e. homonyms) are chained. In the -- case of overloaded entities, this chain holds all the possible meanings -- of a given identifier. The process of overload resolution uses type -- information to select from this chain the unique meaning of a given -- identifier. -- Entities are also chained in their scope, through the Next_Entity link. -- As a consequence, the name space is organized as a sparse matrix, where -- each row corresponds to a scope, and each column to a source identifier. -- Open scopes, that is to say scopes currently being compiled, have their -- corresponding rows of entities in order, innermost scope first. -- The scopes of packages that are mentioned in context clauses appear in -- no particular order, interspersed among open scopes. This is because -- in the course of analyzing the context of a compilation, a package -- declaration is first an open scope, and subsequently an element of the -- context. If subunits or child units are present, a parent unit may -- appear under various guises at various times in the compilation. -- When the compilation of the innermost scope is complete, the entities -- defined therein are no longer visible. If the scope is not a package -- declaration, these entities are never visible subsequently, and can be -- removed from visibility chains. If the scope is a package declaration, -- its visible declarations may still be accessible. Therefore the entities -- defined in such a scope are left on the visibility chains, and only -- their visibility (immediately visibility or potential use-visibility) -- is affected. -- The ordering of homonyms on their chain does not necessarily follow -- the order of their corresponding scopes on the scope stack. For -- example, if package P and the enclosing scope both contain entities -- named E, then when compiling the package body the chain for E will -- hold the global entity first, and the local one (corresponding to -- the current inner scope) next. As a result, name resolution routines -- do not assume any relative ordering of the homonym chains, either -- for scope nesting or to order of appearance of context clauses. -- When compiling a child unit, entities in the parent scope are always -- immediately visible. When compiling the body of a child unit, private -- entities in the parent must also be made immediately visible. There -- are separate routines to make the visible and private declarations -- visible at various times (see package Sem_Ch7). -- +--------+ +-----+ -- | In use |-------->| EU1 |--------------------------> -- +--------+ +-----+ -- | | -- +--------+ +-----+ +-----+ -- | Stand. |---------------->| ES1 |--------------->| ES2 |---> -- +--------+ +-----+ +-----+ -- | | -- +---------+ | +-----+ -- | with'ed |------------------------------>| EW2 |---> -- +---------+ | +-----+ -- | | -- +--------+ +-----+ +-----+ -- | Scope2 |---------------->| E12 |--------------->| E22 |---> -- +--------+ +-----+ +-----+ -- | | -- +--------+ +-----+ +-----+ -- | Scope1 |---------------->| E11 |--------------->| E12 |---> -- +--------+ +-----+ +-----+ -- ^ | | -- | | | -- | +---------+ | | -- | | with'ed |-----------------------------------------> -- | +---------+ | | -- | | | -- Scope stack | | -- (innermost first) | | -- +----------------------------+ -- Names table => | Id1 | | | | Id2 | -- +----------------------------+ -- Name resolution must deal with several syntactic forms: simple names, -- qualified names, indexed names, and various forms of calls. -- Each identifier points to an entry in the names table. The resolution -- of a simple name consists in traversing the homonym chain, starting -- from the names table. If an entry is immediately visible, it is the one -- designated by the identifier. If only potentially use-visible entities -- are on the chain, we must verify that they do not hide each other. If -- the entity we find is overloadable, we collect all other overloadable -- entities on the chain as long as they are not hidden. -- -- To resolve expanded names, we must find the entity at the intersection -- of the entity chain for the scope (the prefix) and the homonym chain -- for the selector. In general, homonym chains will be much shorter than -- entity chains, so it is preferable to start from the names table as -- well. If the entity found is overloadable, we must collect all other -- interpretations that are defined in the scope denoted by the prefix. -- For records, protected types, and tasks, their local entities are -- removed from visibility chains on exit from the corresponding scope. -- From the outside, these entities are always accessed by selected -- notation, and the entity chain for the record type, protected type, -- etc. is traversed sequentially in order to find the designated entity. -- The discriminants of a type and the operations of a protected type or -- task are unchained on exit from the first view of the type, (such as -- a private or incomplete type declaration, or a protected type speci- -- fication) and re-chained when compiling the second view. -- In the case of operators, we do not make operators on derived types -- explicit. As a result, the notation P."+" may denote either a user- -- defined function with name "+", or else an implicit declaration of the -- operator "+" in package P. The resolution of expanded names always -- tries to resolve an operator name as such an implicitly defined entity, -- in addition to looking for explicit declarations. -- All forms of names that denote entities (simple names, expanded names, -- character literals in some cases) have a Entity attribute, which -- identifies the entity denoted by the name. --------------------- -- The Scope Stack -- --------------------- -- The Scope stack keeps track of the scopes currently been compiled. -- Every entity that contains declarations (including records) is placed -- on the scope stack while it is being processed, and removed at the end. -- Whenever a non-package scope is exited, the entities defined therein -- are removed from the visibility table, so that entities in outer scopes -- become visible (see previous description). On entry to Sem, the scope -- stack only contains the package Standard. As usual, subunits complicate -- this picture ever so slightly. -- The Rtsfind mechanism can force a call to Semantics while another -- compilation is in progress. The unit retrieved by Rtsfind must be -- compiled in its own context, and has no access to the visibility of -- the unit currently being compiled. The procedures Save_Scope_Stack and -- Restore_Scope_Stack make entities in current open scopes invisible -- before compiling the retrieved unit, and restore the compilation -- environment afterwards. ------------------------ -- Compiling subunits -- ------------------------ -- Subunits must be compiled in the environment of the corresponding stub, -- that is to say with the same visibility into the parent (and its -- context) that is available at the point of the stub declaration, but -- with the additional visibility provided by the context clause of the -- subunit itself. As a result, compilation of a subunit forces compilation -- of the parent (see description in lib-). At the point of the stub -- declaration, Analyze is called recursively to compile the proper body of -- the subunit, but without reinitializing the names table, nor the scope -- stack (i.e. standard is not pushed on the stack). In this fashion the -- context of the subunit is added to the context of the parent, and the -- subunit is compiled in the correct environment. Note that in the course -- of processing the context of a subunit, Standard will appear twice on -- the scope stack: once for the parent of the subunit, and once for the -- unit in the context clause being compiled. However, the two sets of -- entities are not linked by homonym chains, so that the compilation of -- any context unit happens in a fresh visibility environment. ------------------------------- -- Processing of USE Clauses -- ------------------------------- -- Every defining occurrence has a flag indicating if it is potentially use -- visible. Resolution of simple names examines this flag. The processing -- of use clauses consists in setting this flag on all visible entities -- defined in the corresponding package. On exit from the scope of the use -- clause, the corresponding flag must be reset. However, a package may -- appear in several nested use clauses (pathological but legal, alas!) -- which forces us to use a slightly more involved scheme: -- a) The defining occurrence for a package holds a flag -In_Use- to -- indicate that it is currently in the scope of a use clause. If a -- redundant use clause is encountered, then the corresponding occurrence -- of the package name is flagged -Redundant_Use-. -- b) On exit from a scope, the use clauses in its declarative part are -- scanned. The visibility flag is reset in all entities declared in -- package named in a use clause, as long as the package is not flagged -- as being in a redundant use clause (in which case the outer use -- clause is still in effect, and the direct visibility of its entities -- must be retained). -- Note that entities are not removed from their homonym chains on exit -- from the package specification. A subsequent use clause does not need -- to rechain the visible entities, but only to establish their direct -- visibility. ----------------------------------- -- Handling private declarations -- ----------------------------------- -- The principle that each entity has a single defining occurrence clashes -- with the presence of two separate definitions for private types: the -- first is the private type declaration, and second is the full type -- declaration. It is important that all references to the type point to -- the same defining occurrence, namely the first one. To enforce the two -- separate views of the entity, the corresponding information is swapped -- between the two declarations. Outside of the package, the defining -- occurrence only contains the private declaration information, while in -- the private part and the body of the package the defining occurrence -- contains the full declaration. To simplify the swap, the defining -- occurrence that currently holds the private declaration points to the -- full declaration. During semantic processing the defining occurrence -- also points to a list of private dependents, that is to say access types -- or composite types whose designated types or component types are -- subtypes or derived types of the private type in question. After the -- full declaration has been seen, the private dependents are updated to -- indicate that they have full definitions. ------------------------------------ -- Handling of Undefined Messages -- ------------------------------------ -- In normal mode, only the first use of an undefined identifier generates -- a message. The table Urefs is used to record error messages that have -- been issued so that second and subsequent ones do not generate further -- messages. However, the second reference causes text to be added to the -- original undefined message noting "(more references follow)". The -- full error list option (-gnatf) forces messages to be generated for -- every reference and disconnects the use of this table. type Uref_Entry is record Node : Node_Id; -- Node for identifier for which original message was posted. The -- Chars field of this identifier is used to detect later references -- to the same identifier. Err : Error_Msg_Id; -- Records error message Id of original undefined message. Reset to -- No_Error_Msg after the second occurrence, where it is used to add -- text to the original message as described above. Nvis : Boolean; -- Set if the message is not visible rather than undefined Loc : Source_Ptr; -- Records location of error message. Used to make sure that we do -- not consider a, b : undefined as two separate instances, which -- would otherwise happen, since the parser converts this sequence -- to a : undefined; b : undefined. end record; package Urefs is new Table.Table ( Table_Component_Type => Uref_Entry, Table_Index_Type => Nat, Table_Low_Bound => 1, Table_Initial => 10, Table_Increment => 100, Table_Name => "Urefs"); Candidate_Renaming : Entity_Id; -- Holds a candidate interpretation that appears in a subprogram renaming -- declaration and does not match the given specification, but matches at -- least on the first formal. Allows better error message when given -- specification omits defaulted parameters, a common error. ----------------------- -- Local Subprograms -- ----------------------- procedure Analyze_Generic_Renaming (N : Node_Id; K : Entity_Kind); -- Common processing for all three kinds of generic renaming declarations. -- Enter new name and indicate that it renames the generic unit. procedure Analyze_Renamed_Character (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean); -- Renamed entity is given by a character literal, which must belong -- to the return type of the new entity. Is_Body indicates whether the -- declaration is a renaming_as_body. If the original declaration has -- already been frozen (because of an intervening body, e.g.) the body of -- the function must be built now. The same applies to the following -- various renaming procedures. procedure Analyze_Renamed_Dereference (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean); -- Renamed entity is given by an explicit dereference. Prefix must be a -- conformant access_to_subprogram type. procedure Analyze_Renamed_Entry (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean); -- If the renamed entity in a subprogram renaming is an entry or protected -- subprogram, build a body for the new entity whose only statement is a -- call to the renamed entity. procedure Analyze_Renamed_Family_Member (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean); -- Used when the renamed entity is an indexed component. The prefix must -- denote an entry family. procedure Analyze_Renamed_Primitive_Operation (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean); -- If the renamed entity in a subprogram renaming is a primitive operation -- or a class-wide operation in prefix form, save the target object, which -- must be added to the list of actuals in any subsequent call. function Applicable_Use (Pack_Name : Node_Id) return Boolean; -- Common code to Use_One_Package and Set_Use, to determine whether use -- clause must be processed. Pack_Name is an entity name that references -- the package in question. procedure Attribute_Renaming (N : Node_Id); -- Analyze renaming of attribute as subprogram. The renaming declaration N -- is rewritten as a subprogram body that returns the attribute reference -- applied to the formals of the function. procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id); -- Set Entity, with style check if need be. For a discriminant reference, -- replace by the corresponding discriminal, i.e. the parameter of the -- initialization procedure that corresponds to the discriminant. procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id); -- A renaming_as_body may occur after the entity of the original decla- -- ration has been frozen. In that case, the body of the new entity must -- be built now, because the usual mechanism of building the renamed -- body at the point of freezing will not work. Subp is the subprogram -- for which N provides the Renaming_As_Body. procedure Check_In_Previous_With_Clause (N : Node_Id; Nam : Node_Id); -- N is a use_package clause and Nam the package name, or N is a use_type -- clause and Nam is the prefix of the type name. In either case, verify -- that the package is visible at that point in the context: either it -- appears in a previous with_clause, or because it is a fully qualified -- name and the root ancestor appears in a previous with_clause. procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id); -- Verify that the entity in a renaming declaration that is a library unit -- is itself a library unit and not a nested unit or subunit. Also check -- that if the renaming is a child unit of a generic parent, then the -- renamed unit must also be a child unit of that parent. Finally, verify -- that a renamed generic unit is not an implicit child declared within -- an instance of the parent. procedure Chain_Use_Clause (N : Node_Id); -- Chain use clause onto list of uses clauses headed by First_Use_Clause in -- the proper scope table entry. This is usually the current scope, but it -- will be an inner scope when installing the use clauses of the private -- declarations of a parent unit prior to compiling the private part of a -- child unit. This chain is traversed when installing/removing use clauses -- when compiling a subunit or instantiating a generic body on the fly, -- when it is necessary to save and restore full environments. function Has_Implicit_Character_Literal (N : Node_Id) return Boolean; -- Find a type derived from Character or Wide_Character in the prefix of N. -- Used to resolved qualified names whose selector is a character literal. function Has_Private_With (E : Entity_Id) return Boolean; -- Ada 2005 (AI-262): Determines if the current compilation unit has a -- private with on E. procedure Find_Expanded_Name (N : Node_Id); -- The input is a selected component known to be an expanded name. Verify -- legality of selector given the scope denoted by prefix, and change node -- N into a expanded name with a properly set Entity field. function Find_Renamed_Entity (N : Node_Id; Nam : Node_Id; New_S : Entity_Id; Is_Actual : Boolean := False) return Entity_Id; -- Find the renamed entity that corresponds to the given parameter profile -- in a subprogram renaming declaration. The renamed entity may be an -- operator, a subprogram, an entry, or a protected operation. Is_Actual -- indicates that the renaming is the one generated for an actual subpro- -- gram in an instance, for which special visibility checks apply. function Has_Implicit_Operator (N : Node_Id) return Boolean; -- N is an expanded name whose selector is an operator name (e.g. P."+"). -- declarative part contains an implicit declaration of an operator if it -- has a declaration of a type to which one of the predefined operators -- apply. The existence of this routine is an implementation artifact. A -- more straightforward but more space-consuming choice would be to make -- all inherited operators explicit in the symbol table. procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id); -- A subprogram defined by a renaming declaration inherits the parameter -- profile of the renamed entity. The subtypes given in the subprogram -- specification are discarded and replaced with those of the renamed -- subprogram, which are then used to recheck the default values. function Is_Appropriate_For_Record (T : Entity_Id) return Boolean; -- Prefix is appropriate for record if it is of a record type, or an access -- to such. function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean; -- True if it is of a task type, a protected type, or else an access to one -- of these types. procedure Note_Redundant_Use (Clause : Node_Id); -- Mark the name in a use clause as redundant if the corresponding entity -- is already use-visible. Emit a warning if the use clause comes from -- source and the proper warnings are enabled. procedure Premature_Usage (N : Node_Id); -- Diagnose usage of an entity before it is visible procedure Use_One_Package (P : Entity_Id; N : Node_Id); -- Make visible entities declared in package P potentially use-visible -- in the current context. Also used in the analysis of subunits, when -- re-installing use clauses of parent units. N is the use_clause that -- names P (and possibly other packages). procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False); -- Id is the subtype mark from a use type clause. This procedure makes -- the primitive operators of the type potentially use-visible. The -- boolean flag Installed indicates that the clause is being reinstalled -- after previous analysis, and primitive operations are already chained -- on the Used_Operations list of the clause. procedure Write_Info; -- Write debugging information on entities declared in current scope -------------------------------- -- Analyze_Exception_Renaming -- -------------------------------- -- The language only allows a single identifier, but the tree holds an -- identifier list. The parser has already issued an error message if -- there is more than one element in the list. procedure Analyze_Exception_Renaming (N : Node_Id) is Id : constant Node_Id := Defining_Identifier (N); Nam : constant Node_Id := Name (N); begin Check_SPARK_Restriction ("exception renaming is not allowed", N); Enter_Name (Id); Analyze (Nam); Set_Ekind (Id, E_Exception); Set_Exception_Code (Id, Uint_0); Set_Etype (Id, Standard_Exception_Type); Set_Is_Pure (Id, Is_Pure (Current_Scope)); if not Is_Entity_Name (Nam) or else Ekind (Entity (Nam)) /= E_Exception then Error_Msg_N ("invalid exception name in renaming", Nam); else if Present (Renamed_Object (Entity (Nam))) then Set_Renamed_Object (Id, Renamed_Object (Entity (Nam))); else Set_Renamed_Object (Id, Entity (Nam)); end if; end if; 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; Check_SPARK_Restriction ("generic renaming is not allowed", N); Generate_Definition (New_P); if Current_Scope /= Standard_Standard then Set_Is_Pure (New_P, Is_Pure (Current_Scope)); end if; if Nkind (Name (N)) = N_Selected_Component then Check_Generic_Child_Unit (Name (N), Inst); else Analyze (Name (N)); end if; if not Is_Entity_Name (Name (N)) then Error_Msg_N ("expect entity name in renaming declaration", Name (N)); Old_P := Any_Id; else Old_P := Entity (Name (N)); end if; Enter_Name (New_P); Set_Ekind (New_P, K); if Etype (Old_P) = Any_Type then null; elsif Ekind (Old_P) /= K then Error_Msg_N ("invalid generic unit name", Name (N)); else if Present (Renamed_Object (Old_P)) then Set_Renamed_Object (New_P, Renamed_Object (Old_P)); else Set_Renamed_Object (New_P, Old_P); end if; Set_Is_Pure (New_P, Is_Pure (Old_P)); Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P)); Set_Etype (New_P, Etype (Old_P)); Set_Has_Completion (New_P); if In_Open_Scopes (Old_P) then Error_Msg_N ("within its scope, generic denotes its instance", N); end if; Check_Library_Unit_Renaming (N, Old_P); end if; end Analyze_Generic_Renaming; ----------------------------- -- Analyze_Object_Renaming -- ----------------------------- procedure Analyze_Object_Renaming (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Id : constant Entity_Id := Defining_Identifier (N); Dec : Node_Id; Nam : constant Node_Id := Name (N); T : Entity_Id; T2 : Entity_Id; procedure Check_Constrained_Object; -- If the nominal type is unconstrained but the renamed object is -- constrained, as can happen with renaming an explicit dereference or -- a function return, build a constrained subtype from the object. If -- the renaming is for a formal in an accept statement, the analysis -- has already established its actual subtype. This is only relevant -- if the renamed object is an explicit dereference. function In_Generic_Scope (E : Entity_Id) return Boolean; -- Determine whether entity E is inside a generic cope ------------------------------ -- Check_Constrained_Object -- ------------------------------ procedure Check_Constrained_Object is Subt : Entity_Id; begin if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference) and then Is_Composite_Type (Etype (Nam)) and then not Is_Constrained (Etype (Nam)) and then not Has_Unknown_Discriminants (Etype (Nam)) and then Expander_Active then -- If Actual_Subtype is already set, nothing to do if Ekind_In (Id, E_Variable, E_Constant) and then Present (Actual_Subtype (Id)) then null; -- A renaming of an unchecked union does not have an -- actual subtype. elsif Is_Unchecked_Union (Etype (Nam)) then null; else Subt := Make_Temporary (Loc, 'T'); Remove_Side_Effects (Nam); Insert_Action (N, Make_Subtype_Declaration (Loc, Defining_Identifier => Subt, Subtype_Indication => Make_Subtype_From_Expr (Nam, Etype (Nam)))); Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc)); Set_Etype (Nam, Subt); end if; end if; end Check_Constrained_Object; ---------------------- -- In_Generic_Scope -- ---------------------- function In_Generic_Scope (E : Entity_Id) return Boolean is S : Entity_Id; begin S := Scope (E); while Present (S) and then S /= Standard_Standard loop if Is_Generic_Unit (S) then return True; end if; S := Scope (S); end loop; return False; end In_Generic_Scope; -- Start of processing for Analyze_Object_Renaming begin if Nam = Error then return; end if; Check_SPARK_Restriction ("object renaming is not allowed", N); Set_Is_Pure (Id, Is_Pure (Current_Scope)); Enter_Name (Id); -- The renaming of a component that depends on a discriminant requires -- an actual subtype, because in subsequent use of the object Gigi will -- be unable to locate the actual bounds. This explicit step is required -- when the renaming is generated in removing side effects of an -- already-analyzed expression. if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then T := Etype (Nam); Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam); if Present (Dec) then Insert_Action (N, Dec); T := Defining_Identifier (Dec); Set_Etype (Nam, T); end if; -- Complete analysis of the subtype mark in any case, for ASIS use if Present (Subtype_Mark (N)) then Find_Type (Subtype_Mark (N)); end if; elsif Present (Subtype_Mark (N)) then Find_Type (Subtype_Mark (N)); T := Entity (Subtype_Mark (N)); Analyze (Nam); -- Reject renamings of conversions unless the type is tagged, or -- the conversion is implicit (which can occur for cases of anonymous -- access types in Ada 2012). if Nkind (Nam) = N_Type_Conversion and then Comes_From_Source (Nam) and then not Is_Tagged_Type (T) then Error_Msg_N ("renaming of conversion only allowed for tagged types", Nam); end if; Resolve (Nam, T); -- If the renamed object is a function call of a limited type, -- the expansion of the renaming is complicated by the presence -- of various temporaries and subtypes that capture constraints -- of the renamed object. Rewrite node as an object declaration, -- whose expansion is simpler. Given that the object is limited -- there is no copy involved and no performance hit. if Nkind (Nam) = N_Function_Call and then Is_Immutably_Limited_Type (Etype (Nam)) and then not Is_Constrained (Etype (Nam)) and then Comes_From_Source (N) then Set_Etype (Id, T); Set_Ekind (Id, E_Constant); Rewrite (N, Make_Object_Declaration (Loc, Defining_Identifier => Id, Constant_Present => True, Object_Definition => New_Occurrence_Of (Etype (Nam), Loc), Expression => Relocate_Node (Nam))); return; end if; -- Ada 2012 (AI05-149): Reject renaming of an anonymous access object -- when renaming declaration has a named access type. The Ada 2012 -- coverage rules allow an anonymous access type in the context of -- an expected named general access type, but the renaming rules -- require the types to be the same. (An exception is when the type -- of the renaming is also an anonymous access type, which can only -- happen due to a renaming created by the expander.) if Nkind (Nam) = N_Type_Conversion and then not Comes_From_Source (Nam) and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type and then Ekind (T) /= E_Anonymous_Access_Type then Wrong_Type (Expression (Nam), T); -- Should we give better error??? end if; -- Check that a class-wide object is not being renamed as an object -- of a specific type. The test for access types is needed to exclude -- cases where the renamed object is a dynamically tagged access -- result, such as occurs in certain expansions. if Is_Tagged_Type (T) then Check_Dynamically_Tagged_Expression (Expr => Nam, Typ => T, Related_Nod => N); end if; -- Ada 2005 (AI-230/AI-254): Access renaming else pragma Assert (Present (Access_Definition (N))); T := Access_Definition (Related_Nod => N, N => Access_Definition (N)); Analyze (Nam); -- Ada 2005 AI05-105: if the declaration has an anonymous access -- type, the renamed object must also have an anonymous type, and -- this is a name resolution rule. This was implicit in the last part -- of the first sentence in 8.5.1(3/2), and is made explicit by this -- recent AI. if not Is_Overloaded (Nam) then if Ekind (Etype (Nam)) /= Ekind (T) then Error_Msg_N ("expect anonymous access type in object renaming", N); end if; else declare I : Interp_Index; It : Interp; Typ : Entity_Id := Empty; Seen : Boolean := False; begin Get_First_Interp (Nam, I, It); while Present (It.Typ) loop -- Renaming is ambiguous if more than one candidate -- interpretation is type-conformant with the context. if Ekind (It.Typ) = Ekind (T) then if Ekind (T) = E_Anonymous_Access_Subprogram_Type and then Type_Conformant (Designated_Type (T), Designated_Type (It.Typ)) then if not Seen then Seen := True; else Error_Msg_N ("ambiguous expression in renaming", Nam); end if; elsif Ekind (T) = E_Anonymous_Access_Type and then Covers (Designated_Type (T), Designated_Type (It.Typ)) then if not Seen then Seen := True; else Error_Msg_N ("ambiguous expression in renaming", Nam); end if; end if; if Covers (T, It.Typ) then Typ := It.Typ; Set_Etype (Nam, Typ); Set_Is_Overloaded (Nam, False); end if; end if; Get_Next_Interp (I, It); end loop; end; end if; Resolve (Nam, T); -- Ada 2005 (AI-231): "In the case where the type is defined by an -- access_definition, the renamed entity shall be of an access-to- -- constant type if and only if the access_definition defines an -- access-to-constant type" ARM 8.5.1(4) if Constant_Present (Access_Definition (N)) and then not Is_Access_Constant (Etype (Nam)) then Error_Msg_N ("(Ada 2005): the renamed object is not " & "access-to-constant (RM 8.5.1(6))", N); elsif not Constant_Present (Access_Definition (N)) and then Is_Access_Constant (Etype (Nam)) then Error_Msg_N ("(Ada 2005): the renamed object is not " & "access-to-variable (RM 8.5.1(6))", N); end if; if Is_Access_Subprogram_Type (Etype (Nam)) then Check_Subtype_Conformant (Designated_Type (T), Designated_Type (Etype (Nam))); elsif not Subtypes_Statically_Match (Designated_Type (T), Available_View (Designated_Type (Etype (Nam)))) then Error_Msg_N ("subtype of renamed object does not statically match", N); end if; end if; -- Special processing for renaming function return object. Some errors -- and warnings are produced only for calls that come from source. if Nkind (Nam) = N_Function_Call then case Ada_Version is -- Usage is illegal in Ada 83 when Ada_83 => if Comes_From_Source (Nam) then Error_Msg_N ("(Ada 83) cannot rename function return object", Nam); end if; -- In Ada 95, warn for odd case of renaming parameterless function -- call if this is not a limited type (where this is useful). when others => if Warn_On_Object_Renames_Function and then No (Parameter_Associations (Nam)) and then not Is_Limited_Type (Etype (Nam)) and then Comes_From_Source (Nam) then Error_Msg_N ("?renaming function result object is suspicious", Nam); Error_Msg_NE ("\?function & will be called only once", Nam, Entity (Name (Nam))); Error_Msg_N -- CODEFIX ("\?suggest using an initialized constant object instead", Nam); end if; end case; end if; Check_Constrained_Object; -- An object renaming requires an exact match of the type. Class-wide -- matching is not allowed. if Is_Class_Wide_Type (T) and then Base_Type (Etype (Nam)) /= Base_Type (T) then Wrong_Type (Nam, T); end if; T2 := Etype (Nam); -- Ada 2005 (AI-326): Handle wrong use of incomplete type if Nkind (Nam) = N_Explicit_Dereference and then Ekind (Etype (T2)) = E_Incomplete_Type then Error_Msg_NE ("invalid use of incomplete type&", Id, T2); return; elsif Ekind (Etype (T)) = E_Incomplete_Type then Error_Msg_NE ("invalid use of incomplete type&", Id, T); return; end if; -- Ada 2005 (AI-327) if Ada_Version >= Ada_2005 and then Nkind (Nam) = N_Attribute_Reference and then Attribute_Name (Nam) = Name_Priority then null; elsif Ada_Version >= Ada_2005 and then Nkind (Nam) in N_Has_Entity then declare Nam_Decl : Node_Id; Nam_Ent : Entity_Id; begin if Nkind (Nam) = N_Attribute_Reference then Nam_Ent := Entity (Prefix (Nam)); else Nam_Ent := Entity (Nam); end if; Nam_Decl := Parent (Nam_Ent); if Has_Null_Exclusion (N) and then not Has_Null_Exclusion (Nam_Decl) then -- Ada 2005 (AI-423): If the object name denotes a generic -- formal object of a generic unit G, and the object renaming -- declaration occurs within the body of G or within the body -- of a generic unit declared within the declarative region -- of G, then the declaration of the formal object of G must -- have a null exclusion or a null-excluding subtype. if Is_Formal_Object (Nam_Ent) and then In_Generic_Scope (Id) then if not Can_Never_Be_Null (Etype (Nam_Ent)) then Error_Msg_N ("renamed formal does not exclude `NULL` " & "(RM 8.5.1(4.6/2))", N); elsif In_Package_Body (Scope (Id)) then Error_Msg_N ("formal object does not have a null exclusion" & "(RM 8.5.1(4.6/2))", N); end if; -- Ada 2005 (AI-423): Otherwise, the subtype of the object name -- shall exclude null. elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then Error_Msg_N ("renamed object does not exclude `NULL` " & "(RM 8.5.1(4.6/2))", N); -- An instance is illegal if it contains a renaming that -- excludes null, and the actual does not. The renaming -- declaration has already indicated that the declaration -- of the renamed actual in the instance will raise -- constraint_error. elsif Nkind (Nam_Decl) = N_Object_Declaration and then In_Instance and then Present (Corresponding_Generic_Association (Nam_Decl)) and then Nkind (Expression (Nam_Decl)) = N_Raise_Constraint_Error then Error_Msg_N ("renamed actual does not exclude `NULL` " & "(RM 8.5.1(4.6/2))", N); -- Finally, if there is a null exclusion, the subtype mark -- must not be null-excluding. elsif No (Access_Definition (N)) and then Can_Never_Be_Null (T) then Error_Msg_NE ("`NOT NULL` not allowed (& already excludes null)", N, T); end if; elsif Can_Never_Be_Null (T) and then not Can_Never_Be_Null (Etype (Nam_Ent)) then Error_Msg_N ("renamed object does not exclude `NULL` " & "(RM 8.5.1(4.6/2))", N); elsif Has_Null_Exclusion (N) and then No (Access_Definition (N)) and then Can_Never_Be_Null (T) then Error_Msg_NE ("`NOT NULL` not allowed (& already excludes null)", N, T); end if; end; end if; Set_Ekind (Id, E_Variable); -- Initialize the object size and alignment. Note that we used to call -- Init_Size_Align here, but that's wrong for objects which have only -- an Esize, not an RM_Size field! Init_Object_Size_Align (Id); if T = Any_Type or else Etype (Nam) = Any_Type then return; -- Verify that the renamed entity is an object or a function call. It -- may have been rewritten in several ways. elsif Is_Object_Reference (Nam) then if Comes_From_Source (N) and then Is_Dependent_Component_Of_Mutable_Object (Nam) then Error_Msg_N ("illegal renaming of discriminant-dependent component", Nam); end if; -- A static function call may have been folded into a literal elsif Nkind (Original_Node (Nam)) = N_Function_Call -- When expansion is disabled, attribute reference is not -- rewritten as function call. Otherwise it may be rewritten -- as a conversion, so check original node. or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference and then Is_Function_Attribute_Name (Attribute_Name (Original_Node (Nam)))) -- Weird but legal, equivalent to renaming a function call. -- Illegal if the literal is the result of constant-folding an -- attribute reference that is not a function. or else (Is_Entity_Name (Nam) and then Ekind (Entity (Nam)) = E_Enumeration_Literal and then Nkind (Original_Node (Nam)) /= N_Attribute_Reference) or else (Nkind (Nam) = N_Type_Conversion and then Is_Tagged_Type (Entity (Subtype_Mark (Nam)))) then null; elsif Nkind (Nam) = N_Type_Conversion then Error_Msg_N ("renaming of conversion only allowed for tagged types", Nam); -- Ada 2005 (AI-327) elsif Ada_Version >= Ada_2005 and then Nkind (Nam) = N_Attribute_Reference and then Attribute_Name (Nam) = Name_Priority then null; -- Allow internally generated x'Reference expression elsif Nkind (Nam) = N_Reference then null; else Error_Msg_N ("expect object name in renaming", Nam); end if; Set_Etype (Id, T2); if not Is_Variable (Nam) then Set_Ekind (Id, E_Constant); Set_Never_Set_In_Source (Id, True); Set_Is_True_Constant (Id, True); end if; Set_Renamed_Object (Id, Nam); Analyze_Dimension (N); end Analyze_Object_Renaming; ------------------------------ -- Analyze_Package_Renaming -- ------------------------------ procedure Analyze_Package_Renaming (N : Node_Id) is New_P : constant Entity_Id := Defining_Entity (N); Old_P : Entity_Id; Spec : Node_Id; begin if Name (N) = Error then return; end if; -- Apply Text_IO kludge here since we may be renaming a child of Text_IO Text_IO_Kludge (Name (N)); if Current_Scope /= Standard_Standard then Set_Is_Pure (New_P, Is_Pure (Current_Scope)); end if; Enter_Name (New_P); Analyze (Name (N)); if Is_Entity_Name (Name (N)) then Old_P := Entity (Name (N)); else Old_P := Any_Id; end if; if Etype (Old_P) = Any_Type then Error_Msg_N ("expect package name in renaming", Name (N)); elsif Ekind (Old_P) /= E_Package and then not (Ekind (Old_P) = E_Generic_Package and then In_Open_Scopes (Old_P)) then if Ekind (Old_P) = E_Generic_Package then Error_Msg_N ("generic package cannot be renamed as a package", Name (N)); else Error_Msg_Sloc := Sloc (Old_P); Error_Msg_NE ("expect package name in renaming, found& declared#", Name (N), Old_P); end if; -- Set basic attributes to minimize cascaded errors Set_Ekind (New_P, E_Package); Set_Etype (New_P, Standard_Void_Type); -- Here for OK package renaming else -- Entities in the old package are accessible through the renaming -- entity. The simplest implementation is to have both packages share -- the entity list. Set_Ekind (New_P, E_Package); Set_Etype (New_P, Standard_Void_Type); if Present (Renamed_Object (Old_P)) then Set_Renamed_Object (New_P, Renamed_Object (Old_P)); else Set_Renamed_Object (New_P, Old_P); end if; Set_Has_Completion (New_P); Set_First_Entity (New_P, First_Entity (Old_P)); Set_Last_Entity (New_P, Last_Entity (Old_P)); Set_First_Private_Entity (New_P, First_Private_Entity (Old_P)); Check_Library_Unit_Renaming (N, Old_P); Generate_Reference (Old_P, Name (N)); -- If the renaming is in the visible part of a package, then we set -- Renamed_In_Spec for the renamed package, to prevent giving -- warnings about no entities referenced. Such a warning would be -- overenthusiastic, since clients can see entities in the renamed -- package via the visible package renaming. declare Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit); begin if Ekind (Ent) = E_Package and then not In_Private_Part (Ent) and then In_Extended_Main_Source_Unit (N) and then Ekind (Old_P) = E_Package then Set_Renamed_In_Spec (Old_P); end if; end; -- If this is the renaming declaration of a package instantiation -- within itself, it is the declaration that ends the list of actuals -- for the instantiation. At this point, the subtypes that rename -- the actuals are flagged as generic, to avoid spurious ambiguities -- if the actuals for two distinct formals happen to coincide. If -- the actual is a private type, the subtype has a private completion -- that is flagged in the same fashion. -- Resolution is identical to what is was in the original generic. -- On exit from the generic instance, these are turned into regular -- subtypes again, so they are compatible with types in their class. if not Is_Generic_Instance (Old_P) then return; else Spec := Specification (Unit_Declaration_Node (Old_P)); end if; if Nkind (Spec) = N_Package_Specification and then Present (Generic_Parent (Spec)) and then Old_P = Current_Scope and then Chars (New_P) = Chars (Generic_Parent (Spec)) then declare E : Entity_Id; begin E := First_Entity (Old_P); while Present (E) and then E /= New_P loop if Is_Type (E) and then Nkind (Parent (E)) = N_Subtype_Declaration then Set_Is_Generic_Actual_Type (E); if Is_Private_Type (E) and then Present (Full_View (E)) then Set_Is_Generic_Actual_Type (Full_View (E)); end if; end if; Next_Entity (E); end loop; end; end if; end if; 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); else -- Only mode conformance required for a renaming_as_declaration Check_Mode_Conformant (New_S, Old_S, N); end if; Inherit_Renamed_Profile (New_S, Old_S); -- The prefix can be an arbitrary expression that yields a task type, -- so it must be resolved. Resolve (Prefix (Nam), Scope (Old_S)); end if; Set_Convention (New_S, Convention (Old_S)); Set_Has_Completion (New_S, Inside_A_Generic); if Is_Body then Check_Frozen_Renaming (N, New_S); end if; end Analyze_Renamed_Entry; ----------------------------------- -- Analyze_Renamed_Family_Member -- ----------------------------------- procedure Analyze_Renamed_Family_Member (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean) is Nam : constant Node_Id := Name (N); P : constant Node_Id := Prefix (Nam); Old_S : Entity_Id; begin if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family) or else (Nkind (P) = N_Selected_Component and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family) then if Is_Entity_Name (P) then Old_S := Entity (P); else Old_S := Entity (Selector_Name (P)); end if; if not Entity_Matches_Spec (Old_S, New_S) then Error_Msg_N ("entry family does not match specification", N); elsif Is_Body then Check_Subtype_Conformant (New_S, Old_S, N); Generate_Reference (New_S, Defining_Entity (N), 'b'); Style.Check_Identifier (Defining_Entity (N), New_S); end if; else Error_Msg_N ("no entry family matches specification", N); end if; Set_Has_Completion (New_S, Inside_A_Generic); if Is_Body then Check_Frozen_Renaming (N, New_S); end if; end Analyze_Renamed_Family_Member; ----------------------------------------- -- Analyze_Renamed_Primitive_Operation -- ----------------------------------------- procedure Analyze_Renamed_Primitive_Operation (N : Node_Id; New_S : Entity_Id; Is_Body : Boolean) is Old_S : Entity_Id; function Conforms (Subp : Entity_Id; Ctyp : Conformance_Type) return Boolean; -- Verify that the signatures of the renamed entity and the new entity -- match. The first formal of the renamed entity is skipped because it -- is the target object in any subsequent call. function Conforms (Subp : Entity_Id; Ctyp : Conformance_Type) return Boolean is Old_F : Entity_Id; New_F : Entity_Id; begin if Ekind (Subp) /= Ekind (New_S) then return False; end if; Old_F := Next_Formal (First_Formal (Subp)); New_F := First_Formal (New_S); while Present (Old_F) and then Present (New_F) loop if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then return False; end if; if Ctyp >= Mode_Conformant and then Ekind (Old_F) /= Ekind (New_F) then return False; end if; Next_Formal (New_F); Next_Formal (Old_F); end loop; return True; end Conforms; begin if not Is_Overloaded (Selector_Name (Name (N))) then Old_S := Entity (Selector_Name (Name (N))); if not Conforms (Old_S, Type_Conformant) then Old_S := Any_Id; end if; else -- Find the operation that matches the given signature declare It : Interp; Ind : Interp_Index; begin Old_S := Any_Id; Get_First_Interp (Selector_Name (Name (N)), Ind, It); while Present (It.Nam) loop if Conforms (It.Nam, Type_Conformant) then Old_S := It.Nam; end if; Get_Next_Interp (Ind, It); end loop; end; end if; if Old_S = Any_Id then Error_Msg_N (" no subprogram or entry matches specification", N); else if Is_Body then if not Conforms (Old_S, Subtype_Conformant) then Error_Msg_N ("subtype conformance error in renaming", N); end if; Generate_Reference (New_S, Defining_Entity (N), 'b'); Style.Check_Identifier (Defining_Entity (N), New_S); else -- Only mode conformance required for a renaming_as_declaration if not Conforms (Old_S, Mode_Conformant) then Error_Msg_N ("mode conformance error in renaming", N); end if; end if; -- Inherit_Renamed_Profile (New_S, Old_S); -- The prefix can be an arbitrary expression that yields an -- object, so it must be resolved. Resolve (Prefix (Name (N))); end if; end Analyze_Renamed_Primitive_Operation; --------------------------------- -- Analyze_Subprogram_Renaming -- --------------------------------- procedure Analyze_Subprogram_Renaming (N : Node_Id) is Formal_Spec : constant Node_Id := Corresponding_Formal_Spec (N); Is_Actual : constant Boolean := Present (Formal_Spec); Inst_Node : Node_Id := Empty; Nam : constant Node_Id := Name (N); New_S : Entity_Id; Old_S : Entity_Id := Empty; Rename_Spec : Entity_Id; Save_AV : constant Ada_Version_Type := Ada_Version; Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit; Spec : constant Node_Id := Specification (N); procedure Check_Null_Exclusion (Ren : Entity_Id; Sub : Entity_Id); -- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the -- following AI rules: -- -- If Ren is a renaming of a formal subprogram and one of its -- parameters has a null exclusion, then the corresponding formal -- in Sub must also have one. Otherwise the subtype of the Sub's -- formal parameter must exclude null. -- -- If Ren is a renaming of a formal function and its return -- profile has a null exclusion, then Sub's return profile must -- have one. Otherwise the subtype of Sub's return profile must -- exclude null. function Original_Subprogram (Subp : Entity_Id) return Entity_Id; -- Find renamed entity when the declaration is a renaming_as_body and -- the renamed entity may itself be a renaming_as_body. Used to enforce -- rule that a renaming_as_body is illegal if the declaration occurs -- before the subprogram it completes is frozen, and renaming indirectly -- renames the subprogram itself.(Defect Report 8652/0027). function Check_Class_Wide_Actual return Entity_Id; -- AI05-0071: In an instance, if the actual for a formal type FT with -- unknown discriminants is a class-wide type CT, and the generic has -- a formal subprogram with a box for a primitive operation of FT, -- then the corresponding actual subprogram denoted by the default is a -- class-wide operation whose body is a dispatching call. We replace the -- generated renaming declaration: -- -- procedure P (X : CT) renames P; -- -- by a different renaming and a class-wide operation: -- -- procedure Pr (X : T) renames P; -- renames primitive operation -- procedure P (X : CT); -- class-wide operation -- ... -- procedure P (X : CT) is begin Pr (X); end; -- dispatching call -- -- This rule only applies if there is no explicit visible class-wide -- operation at the point of the instantiation. function Has_Class_Wide_Actual return Boolean; -- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a -- defaulted formal subprogram when the actual for the controlling -- formal type is class-wide. ----------------------------- -- Check_Class_Wide_Actual -- ----------------------------- function Check_Class_Wide_Actual return Entity_Id is Loc : constant Source_Ptr := Sloc (N); F : Entity_Id; Formal_Type : Entity_Id; Actual_Type : Entity_Id; New_Body : Node_Id; New_Decl : Node_Id; Result : Entity_Id; function Make_Call (Prim_Op : Entity_Id) return Node_Id; -- Build dispatching call for body of class-wide operation function Make_Spec return Node_Id; -- Create subprogram specification for declaration and body of -- class-wide operation, using signature of renaming declaration. --------------- -- Make_Call -- --------------- function Make_Call (Prim_Op : Entity_Id) return Node_Id is Actuals : List_Id; F : Node_Id; begin Actuals := New_List; F := First (Parameter_Specifications (Specification (New_Decl))); while Present (F) loop Append_To (Actuals, Make_Identifier (Loc, Chars (Defining_Identifier (F)))); Next (F); end loop; if Ekind_In (Prim_Op, E_Function, E_Operator) then return Make_Simple_Return_Statement (Loc, Expression => Make_Function_Call (Loc, Name => New_Occurrence_Of (Prim_Op, Loc), Parameter_Associations => Actuals)); else return Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Prim_Op, Loc), Parameter_Associations => Actuals); end if; end Make_Call; --------------- -- Make_Spec -- --------------- function Make_Spec return Node_Id is Param_Specs : constant List_Id := Copy_Parameter_List (New_S); begin if Ekind (New_S) = E_Procedure then return Make_Procedure_Specification (Loc, Defining_Unit_Name => Make_Defining_Identifier (Loc, Chars (Defining_Unit_Name (Spec))), Parameter_Specifications => Param_Specs); else return Make_Function_Specification (Loc, Defining_Unit_Name => Make_Defining_Identifier (Loc, Chars (Defining_Unit_Name (Spec))), Parameter_Specifications => Param_Specs, Result_Definition => New_Copy_Tree (Result_Definition (Spec))); end if; end Make_Spec; -- Start of processing for Check_Class_Wide_Actual begin Result := Any_Id; Formal_Type := Empty; Actual_Type := Empty; F := First_Formal (Formal_Spec); while Present (F) loop if Has_Unknown_Discriminants (Etype (F)) and then not Is_Class_Wide_Type (Etype (F)) and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F))) then Formal_Type := Etype (F); Actual_Type := Etype (Get_Instance_Of (Formal_Type)); exit; end if; Next_Formal (F); end loop; if Present (Formal_Type) then -- Create declaration and body for class-wide operation New_Decl := Make_Subprogram_Declaration (Loc, Specification => Make_Spec); New_Body := Make_Subprogram_Body (Loc, Specification => Make_Spec, Declarations => No_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, New_List)); -- Modify Spec and create internal name for renaming of primitive -- operation. Set_Defining_Unit_Name (Spec, Make_Temporary (Loc, 'R')); F := First (Parameter_Specifications (Spec)); while Present (F) loop if Nkind (Parameter_Type (F)) = N_Identifier and then Is_Class_Wide_Type (Entity (Parameter_Type (F))) then Set_Parameter_Type (F, New_Occurrence_Of (Actual_Type, Loc)); end if; Next (F); end loop; New_S := Analyze_Subprogram_Specification (Spec); Result := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual); end if; if Result /= Any_Id then Insert_Before (N, New_Decl); Analyze (New_Decl); -- Add dispatching call to body of class-wide operation Append (Make_Call (Result), Statements (Handled_Statement_Sequence (New_Body))); -- The generated body does not freeze. It is analyzed when the -- generated operation is frozen. This body is only needed if -- expansion is enabled. if Expander_Active then Append_Freeze_Action (Defining_Entity (New_Decl), New_Body); end if; Result := Defining_Entity (New_Decl); end if; -- Return the class-wide operation if one was created return Result; end Check_Class_Wide_Actual; -------------------------- -- Check_Null_Exclusion -- -------------------------- procedure Check_Null_Exclusion (Ren : Entity_Id; Sub : Entity_Id) is Ren_Formal : Entity_Id; Sub_Formal : Entity_Id; begin -- Parameter check Ren_Formal := First_Formal (Ren); Sub_Formal := First_Formal (Sub); while Present (Ren_Formal) and then Present (Sub_Formal) loop if Has_Null_Exclusion (Parent (Ren_Formal)) and then not (Has_Null_Exclusion (Parent (Sub_Formal)) or else Can_Never_Be_Null (Etype (Sub_Formal))) then Error_Msg_NE ("`NOT NULL` required for parameter &", Parent (Sub_Formal), Sub_Formal); end if; Next_Formal (Ren_Formal); Next_Formal (Sub_Formal); end loop; -- Return profile check if Nkind (Parent (Ren)) = N_Function_Specification and then Nkind (Parent (Sub)) = N_Function_Specification and then Has_Null_Exclusion (Parent (Ren)) and then not (Has_Null_Exclusion (Parent (Sub)) or else Can_Never_Be_Null (Etype (Sub))) then Error_Msg_N ("return must specify `NOT NULL`", Result_Definition (Parent (Sub))); end if; end Check_Null_Exclusion; --------------------------- -- Has_Class_Wide_Actual -- --------------------------- function Has_Class_Wide_Actual return Boolean is F_Nam : Entity_Id; F_Spec : Entity_Id; begin if Is_Actual and then Nkind (Nam) in N_Has_Entity and then Present (Entity (Nam)) and then Is_Dispatching_Operation (Entity (Nam)) then F_Nam := First_Entity (Entity (Nam)); F_Spec := First_Formal (Formal_Spec); while Present (F_Nam) and then Present (F_Spec) loop if Is_Controlling_Formal (F_Nam) and then Has_Unknown_Discriminants (Etype (F_Spec)) and then not Is_Class_Wide_Type (Etype (F_Spec)) and then Is_Class_Wide_Type (Get_Instance_Of (Etype (F_Spec))) then return True; end if; Next_Entity (F_Nam); Next_Formal (F_Spec); end loop; end if; return False; end Has_Class_Wide_Actual; ------------------------- -- Original_Subprogram -- ------------------------- function Original_Subprogram (Subp : Entity_Id) return Entity_Id is Orig_Decl : Node_Id; Orig_Subp : Entity_Id; begin -- First case: renamed entity is itself a renaming if Present (Alias (Subp)) then return Alias (Subp); elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration and then Present (Corresponding_Body (Unit_Declaration_Node (Subp))) then -- Check if renamed entity is a renaming_as_body Orig_Decl := Unit_Declaration_Node (Corresponding_Body (Unit_Declaration_Node (Subp))); if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then Orig_Subp := Entity (Name (Orig_Decl)); if Orig_Subp = Rename_Spec then -- Circularity detected return Orig_Subp; else return (Original_Subprogram (Orig_Subp)); end if; else return Subp; end if; else return Subp; end if; end Original_Subprogram; CW_Actual : constant Boolean := Has_Class_Wide_Actual; -- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a -- defaulted formal subprogram when the actual for a related formal -- type is class-wide. -- Start of processing for Analyze_Subprogram_Renaming begin -- We must test for the attribute renaming case before the Analyze -- call because otherwise Sem_Attr will complain that the attribute -- is missing an argument when it is analyzed. if Nkind (Nam) = N_Attribute_Reference then -- In the case of an abstract formal subprogram association, rewrite -- an actual given by a stream attribute as the name of the -- corresponding stream primitive of the type. -- In a generic context the stream operations are not generated, and -- this must be treated as a normal attribute reference, to be -- expanded in subsequent instantiations. if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) and then Full_Expander_Active then declare Stream_Prim : Entity_Id; Prefix_Type : constant Entity_Id := Entity (Prefix (Nam)); begin -- The class-wide forms of the stream attributes are not -- primitive dispatching operations (even though they -- internally dispatch to a stream attribute). if Is_Class_Wide_Type (Prefix_Type) then Error_Msg_N ("attribute must be a primitive dispatching operation", Nam); return; end if; -- Retrieve the primitive subprogram associated with the -- attribute. This can only be a stream attribute, since those -- are the only ones that are dispatching (and the actual for -- an abstract formal subprogram must be dispatching -- operation). begin case Attribute_Name (Nam) is when Name_Input => Stream_Prim := Find_Prim_Op (Prefix_Type, TSS_Stream_Input); when Name_Output => Stream_Prim := Find_Prim_Op (Prefix_Type, TSS_Stream_Output); when Name_Read => Stream_Prim := Find_Prim_Op (Prefix_Type, TSS_Stream_Read); when Name_Write => Stream_Prim := Find_Prim_Op (Prefix_Type, TSS_Stream_Write); when others => Error_Msg_N ("attribute must be a primitive" & " dispatching operation", Nam); return; end case; exception -- If no operation was found, and the type is limited, -- the user should have defined one. when Program_Error => if Is_Limited_Type (Prefix_Type) then Error_Msg_NE ("stream operation not defined for type&", N, Prefix_Type); return; -- Otherwise, compiler should have generated default else raise; end if; end; -- Rewrite the attribute into the name of its corresponding -- primitive dispatching subprogram. We can then proceed with -- the usual processing for subprogram renamings. declare Prim_Name : constant Node_Id := Make_Identifier (Sloc (Nam), Chars => Chars (Stream_Prim)); begin Set_Entity (Prim_Name, Stream_Prim); Rewrite (Nam, Prim_Name); Analyze (Nam); end; end; -- Normal processing for a renaming of an attribute else Attribute_Renaming (N); return; end if; end if; -- Check whether this declaration corresponds to the instantiation -- of a formal subprogram. -- If this is an instantiation, the corresponding actual is frozen and -- error messages can be made more precise. If this is a default -- subprogram, the entity is already established in the generic, and is -- not retrieved by visibility. If it is a default with a box, the -- candidate interpretations, if any, have been collected when building -- the renaming declaration. If overloaded, the proper interpretation is -- determined in Find_Renamed_Entity. If the entity is an operator, -- Find_Renamed_Entity applies additional visibility checks. if Is_Actual then Inst_Node := Unit_Declaration_Node (Formal_Spec); -- Check whether the renaming is for a defaulted actual subprogram -- with a class-wide actual. if CW_Actual then New_S := Analyze_Subprogram_Specification (Spec); Old_S := Check_Class_Wide_Actual; elsif Is_Entity_Name (Nam) and then Present (Entity (Nam)) and then not Comes_From_Source (Nam) and then not Is_Overloaded (Nam) then Old_S := Entity (Nam); New_S := Analyze_Subprogram_Specification (Spec); -- Operator case if Ekind (Entity (Nam)) = E_Operator then -- Box present if Box_Present (Inst_Node) then Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual); -- If there is an immediately visible homonym of the operator -- and the declaration has a default, this is worth a warning -- because the user probably did not intend to get the pre- -- defined operator, visible in the generic declaration. To -- find if there is an intended candidate, analyze the renaming -- again in the current context. elsif Scope (Old_S) = Standard_Standard and then Present (Default_Name (Inst_Node)) then declare Decl : constant Node_Id := New_Copy_Tree (N); Hidden : Entity_Id; begin Set_Entity (Name (Decl), Empty); Analyze (Name (Decl)); Hidden := Find_Renamed_Entity (Decl, Name (Decl), New_S, True); if Present (Hidden) and then In_Open_Scopes (Scope (Hidden)) and then Is_Immediately_Visible (Hidden) and then Comes_From_Source (Hidden) and then Hidden /= Old_S then Error_Msg_Sloc := Sloc (Hidden); Error_Msg_N ("?default subprogram is resolved " & "in the generic declaration " & "(RM 12.6(17))", N); Error_Msg_NE ("\?and will not use & #", N, Hidden); end if; end; end if; end if; else Analyze (Nam); New_S := Analyze_Subprogram_Specification (Spec); end if; else -- Renamed entity must be analyzed first, to avoid being hidden by -- new name (which might be the same in a generic instance). Analyze (Nam); -- The renaming defines a new overloaded entity, which is analyzed -- like a subprogram declaration. New_S := Analyze_Subprogram_Specification (Spec); end if; if Current_Scope /= Standard_Standard then Set_Is_Pure (New_S, Is_Pure (Current_Scope)); end if; Rename_Spec := Find_Corresponding_Spec (N); -- Case of Renaming_As_Body if Present (Rename_Spec) then -- Renaming declaration is the completion of the declaration of -- Rename_Spec. We build an actual body for it at the freezing point. Set_Corresponding_Spec (N, Rename_Spec); -- Deal with special case of stream functions of abstract types -- and interfaces. if Nkind (Unit_Declaration_Node (Rename_Spec)) = N_Abstract_Subprogram_Declaration then -- Input stream functions are abstract if the object type is -- abstract. Similarly, all default stream functions for an -- interface type are abstract. However, these subprograms may -- receive explicit declarations in representation clauses, making -- the attribute subprograms usable as defaults in subsequent -- type extensions. -- In this case we rewrite the declaration to make the subprogram -- non-abstract. We remove the previous declaration, and insert -- the new one at the point of the renaming, to prevent premature -- access to unfrozen types. The new declaration reuses the -- specification of the previous one, and must not be analyzed. pragma Assert (Is_Primitive (Entity (Nam)) and then Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam)))); declare Old_Decl : constant Node_Id := Unit_Declaration_Node (Rename_Spec); New_Decl : constant Node_Id := Make_Subprogram_Declaration (Sloc (N), Specification => Relocate_Node (Specification (Old_Decl))); begin Remove (Old_Decl); Insert_After (N, New_Decl); Set_Is_Abstract_Subprogram (Rename_Spec, False); Set_Analyzed (New_Decl); end; end if; Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S); if Ada_Version = Ada_83 and then Comes_From_Source (N) then Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N); end if; Set_Convention (New_S, Convention (Rename_Spec)); Check_Fully_Conformant (New_S, Rename_Spec); Set_Public_Status (New_S); -- The specification does not introduce new formals, but only -- repeats the formals of the original subprogram declaration. -- For cross-reference purposes, and for refactoring tools, we -- treat the formals of the renaming declaration as body formals. Reference_Body_Formals (Rename_Spec, New_S); -- Indicate that the entity in the declaration functions like the -- corresponding body, and is not a new entity. The body will be -- constructed later at the freeze point, so indicate that the -- completion has not been seen yet. Set_Ekind (New_S, E_Subprogram_Body); New_S := Rename_Spec; Set_Has_Completion (Rename_Spec, False); -- Ada 2005: check overriding indicator if Present (Overridden_Operation (Rename_Spec)) then if Must_Not_Override (Specification (N)) then Error_Msg_NE ("subprogram& overrides inherited operation", N, Rename_Spec); elsif Style_Check and then not Must_Override (Specification (N)) then Style.Missing_Overriding (N, Rename_Spec); end if; elsif Must_Override (Specification (N)) then Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec); end if; -- Normal subprogram renaming (not renaming as body) else Generate_Definition (New_S); New_Overloaded_Entity (New_S); if Is_Entity_Name (Nam) and then Is_Intrinsic_Subprogram (Entity (Nam)) then null; else Check_Delayed_Subprogram (New_S); end if; end if; -- There is no need for elaboration checks on the new entity, which may -- be called before the next freezing point where the body will appear. -- Elaboration checks refer to the real entity, not the one created by -- the renaming declaration. Set_Kill_Elaboration_Checks (New_S, True); if Etype (Nam) = Any_Type then Set_Has_Completion (New_S); return; elsif Nkind (Nam) = N_Selected_Component then -- A prefix of the form A.B can designate an entry of task A, a -- protected operation of protected object A, or finally a primitive -- operation of object A. In the later case, A is an object of some -- tagged type, or an access type that denotes one such. To further -- distinguish these cases, note that the scope of a task entry or -- protected operation is type of the prefix. -- The prefix could be an overloaded function call that returns both -- kinds of operations. This overloading pathology is left to the -- dedicated reader ??? declare T : constant Entity_Id := Etype (Prefix (Nam)); begin if Present (T) and then (Is_Tagged_Type (T) or else (Is_Access_Type (T) and then Is_Tagged_Type (Designated_Type (T)))) and then Scope (Entity (Selector_Name (Nam))) /= T then Analyze_Renamed_Primitive_Operation (N, New_S, Present (Rename_Spec)); return; else -- Renamed entity is an entry or protected operation. For those -- cases an explicit body is built (at the point of freezing of -- this entity) that contains a call to the renamed entity. -- This is not allowed for renaming as body if the renamed -- spec is already frozen (see RM 8.5.4(5) for details). if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then Error_Msg_N ("renaming-as-body cannot rename entry as subprogram", N); Error_Msg_NE ("\since & is already frozen (RM 8.5.4(5))", N, Rename_Spec); else Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec)); end if; return; end if; end; elsif Nkind (Nam) = N_Explicit_Dereference then -- Renamed entity is designated by access_to_subprogram expression. -- Must build body to encapsulate call, as in the entry case. Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec)); return; elsif Nkind (Nam) = N_Indexed_Component then Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec)); return; elsif Nkind (Nam) = N_Character_Literal then Analyze_Renamed_Character (N, New_S, Present (Rename_Spec)); return; elsif not Is_Entity_Name (Nam) or else not Is_Overloadable (Entity (Nam)) then -- Do not mention the renaming if it comes from an instance if not Is_Actual then Error_Msg_N ("expect valid subprogram name in renaming", N); else Error_Msg_NE ("no visible subprogram for formal&", N, Nam); end if; return; end if; -- Find the renamed entity that matches the given specification. Disable -- Ada_83 because there is no requirement of full conformance between -- renamed entity and new entity, even though the same circuit is used. -- This is a bit of a kludge, which introduces a really irregular use of -- Ada_Version[_Explicit]. Would be nice to find cleaner way to do this -- ??? Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95); Ada_Version_Explicit := Ada_Version; if No (Old_S) then Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual); -- The visible operation may be an inherited abstract operation that -- was overridden in the private part, in which case a call will -- dispatch to the overriding operation. Use the overriding one in -- the renaming declaration, to prevent spurious errors below. if Is_Overloadable (Old_S) and then Is_Abstract_Subprogram (Old_S) and then No (DTC_Entity (Old_S)) and then Present (Alias (Old_S)) and then not Is_Abstract_Subprogram (Alias (Old_S)) and then Present (Overridden_Operation (Alias (Old_S))) then Old_S := Alias (Old_S); end if; -- When the renamed subprogram is overloaded and used as an actual -- of a generic, its entity is set to the first available homonym. -- We must first disambiguate the name, then set the proper entity. if Is_Actual and then Is_Overloaded (Nam) then Set_Entity (Nam, Old_S); end if; end if; -- Most common case: subprogram renames subprogram. No body is generated -- in this case, so we must indicate the declaration is complete as is. -- and inherit various attributes of the renamed subprogram. if No (Rename_Spec) then Set_Has_Completion (New_S); Set_Is_Imported (New_S, Is_Imported (Entity (Nam))); Set_Is_Pure (New_S, Is_Pure (Entity (Nam))); Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam))); -- Ada 2005 (AI-423): Check the consistency of null exclusions -- between a subprogram and its correct renaming. -- Note: the Any_Id check is a guard that prevents compiler crashes -- when performing a null exclusion check between a renaming and a -- renamed subprogram that has been found to be illegal. if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then Check_Null_Exclusion (Ren => New_S, Sub => Entity (Nam)); end if; -- Enforce the Ada 2005 rule that the renamed entity cannot require -- overriding. The flag Requires_Overriding is set very selectively -- and misses some other illegal cases. The additional conditions -- checked below are sufficient but not necessary ??? -- The rule does not apply to the renaming generated for an actual -- subprogram in an instance. if Is_Actual then null; -- Guard against previous errors, and omit renamings of predefined -- operators. elsif not Ekind_In (Old_S, E_Function, E_Procedure) then null; elsif Requires_Overriding (Old_S) or else (Is_Abstract_Subprogram (Old_S) and then Present (Find_Dispatching_Type (Old_S)) and then not Is_Abstract_Type (Find_Dispatching_Type (Old_S))) then Error_Msg_N ("renamed entity cannot be " & "subprogram that requires overriding (RM 8.5.4 (5.1))", N); end if; end if; if Old_S /= Any_Id then if Is_Actual and then From_Default (N) then -- This is an implicit reference to the default actual Generate_Reference (Old_S, Nam, Typ => 'i', Force => True); else Generate_Reference (Old_S, Nam); end if; -- For a renaming-as-body, require subtype conformance, but if the -- declaration being completed has not been frozen, then inherit the -- convention of the renamed subprogram prior to checking conformance -- (unless the renaming has an explicit convention established; the -- rule stated in the RM doesn't seem to address this ???). if Present (Rename_Spec) then Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b'); Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec); if not Is_Frozen (Rename_Spec) then if not Has_Convention_Pragma (Rename_Spec) then Set_Convention (New_S, Convention (Old_S)); end if; if Ekind (Old_S) /= E_Operator then Check_Mode_Conformant (New_S, Old_S, Spec); end if; if Original_Subprogram (Old_S) = Rename_Spec then Error_Msg_N ("unfrozen subprogram cannot rename itself ", N); end if; else Check_Subtype_Conformant (New_S, Old_S, Spec); end if; Check_Frozen_Renaming (N, Rename_Spec); -- Check explicitly that renamed entity is not intrinsic, because -- in a generic the renamed body is not built. In this case, -- the renaming_as_body is a completion. if Inside_A_Generic then if Is_Frozen (Rename_Spec) and then Is_Intrinsic_Subprogram (Old_S) then Error_Msg_N ("subprogram in renaming_as_body cannot be intrinsic", Name (N)); end if; Set_Has_Completion (Rename_Spec); end if; elsif Ekind (Old_S) /= E_Operator then -- If this a defaulted subprogram for a class-wide actual there is -- no check for mode conformance, given that the signatures don't -- match (the source mentions T but the actual mentions T'Class). if CW_Actual then null; else Check_Mode_Conformant (New_S, Old_S); end if; if Is_Actual and then Error_Posted (New_S) then Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S); end if; end if; if No (Rename_Spec) then -- The parameter profile of the new entity is that of the renamed -- entity: the subtypes given in the specification are irrelevant. Inherit_Renamed_Profile (New_S, Old_S); -- A call to the subprogram is transformed into a call to the -- renamed entity. This is transitive if the renamed entity is -- itself a renaming. if Present (Alias (Old_S)) then Set_Alias (New_S, Alias (Old_S)); else Set_Alias (New_S, Old_S); end if; -- Note that we do not set Is_Intrinsic_Subprogram if we have a -- renaming as body, since the entity in this case is not an -- intrinsic (it calls an intrinsic, but we have a real body for -- this call, and it is in this body that the required intrinsic -- processing will take place). -- Also, if this is a renaming of inequality, the renamed operator -- is intrinsic, but what matters is the corresponding equality -- operator, which may be user-defined. Set_Is_Intrinsic_Subprogram (New_S, Is_Intrinsic_Subprogram (Old_S) and then (Chars (Old_S) /= Name_Op_Ne or else Ekind (Old_S) = E_Operator or else Is_Intrinsic_Subprogram (Corresponding_Equality (Old_S)))); if Ekind (Alias (New_S)) = E_Operator then Set_Has_Delayed_Freeze (New_S, False); end if; -- If the renaming corresponds to an association for an abstract -- formal subprogram, then various attributes must be set to -- indicate that the renaming is an abstract dispatching operation -- with a controlling type. if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then -- Mark the renaming as abstract here, so Find_Dispatching_Type -- see it as corresponding to a generic association for a -- formal abstract subprogram Set_Is_Abstract_Subprogram (New_S); declare New_S_Ctrl_Type : constant Entity_Id := Find_Dispatching_Type (New_S); Old_S_Ctrl_Type : constant Entity_Id := Find_Dispatching_Type (Old_S); begin if Old_S_Ctrl_Type /= New_S_Ctrl_Type then Error_Msg_NE ("actual must be dispatching subprogram for type&", Nam, New_S_Ctrl_Type); else Set_Is_Dispatching_Operation (New_S); Check_Controlling_Formals (New_S_Ctrl_Type, New_S); -- If the actual in the formal subprogram is itself a -- formal abstract subprogram association, there's no -- dispatch table component or position to inherit. if Present (DTC_Entity (Old_S)) then Set_DTC_Entity (New_S, DTC_Entity (Old_S)); Set_DT_Position (New_S, DT_Position (Old_S)); end if; end if; end; end if; end if; if not Is_Actual and then (Old_S = New_S or else (Nkind (Nam) /= N_Expanded_Name and then Chars (Old_S) = Chars (New_S)) or else (Nkind (Nam) = N_Expanded_Name and then Entity (Prefix (Nam)) = Current_Scope and then Chars (Selector_Name (Nam)) = Chars (New_S))) then Error_Msg_N ("subprogram cannot rename itself", N); end if; Set_Convention (New_S, Convention (Old_S)); if Is_Abstract_Subprogram (Old_S) then if Present (Rename_Spec) then Error_Msg_N ("a renaming-as-body cannot rename an abstract subprogram", N); Set_Has_Completion (Rename_Spec); else Set_Is_Abstract_Subprogram (New_S); end if; end if; Check_Library_Unit_Renaming (N, Old_S); -- Pathological case: procedure renames entry in the scope of its -- task. Entry is given by simple name, but body must be built for -- procedure. Of course if called it will deadlock. if Ekind (Old_S) = E_Entry then Set_Has_Completion (New_S, False); Set_Alias (New_S, Empty); end if; if Is_Actual then Freeze_Before (N, Old_S); Set_Has_Delayed_Freeze (New_S, False); Freeze_Before (N, New_S); -- An abstract subprogram is only allowed as an actual in the case -- where the formal subprogram is also abstract. if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function) and then Is_Abstract_Subprogram (Old_S) and then not Is_Abstract_Subprogram (Formal_Spec) then Error_Msg_N ("abstract subprogram not allowed as generic actual", Nam); end if; end if; else -- A common error is to assume that implicit operators for types are -- defined in Standard, or in the scope of a subtype. In those cases -- where the renamed entity is given with an expanded name, it is -- worth mentioning that operators for the type are not declared in -- the scope given by the prefix. if Nkind (Nam) = N_Expanded_Name and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol and then Scope (Entity (Nam)) = Standard_Standard then declare T : constant Entity_Id := Base_Type (Etype (First_Formal (New_S))); begin Error_Msg_Node_2 := Prefix (Nam); Error_Msg_NE ("operator for type& is not declared in&", Prefix (Nam), T); end; else Error_Msg_NE ("no visible subprogram matches the specification for&", Spec, New_S); end if; if Present (Candidate_Renaming) then declare F1 : Entity_Id; F2 : Entity_Id; T1 : Entity_Id; begin F1 := First_Formal (Candidate_Renaming); F2 := First_Formal (New_S); T1 := First_Subtype (Etype (F1)); while Present (F1) and then Present (F2) loop Next_Formal (F1); Next_Formal (F2); end loop; if Present (F1) and then Present (Default_Value (F1)) then if Present (Next_Formal (F1)) then Error_Msg_NE ("\missing specification for &" & " and other formals with defaults", Spec, F1); else Error_Msg_NE ("\missing specification for &", Spec, F1); end if; end if; if Nkind (Nam) = N_Operator_Symbol and then From_Default (N) then Error_Msg_Node_2 := T1; Error_Msg_NE ("default & on & is not directly visible", Nam, Nam); end if; end; end if; end if; -- Ada 2005 AI 404: if the new subprogram is dispatching, verify that -- controlling access parameters are known non-null for the renamed -- subprogram. Test also applies to a subprogram instantiation that -- is dispatching. Test is skipped if some previous error was detected -- that set Old_S to Any_Id. if Ada_Version >= Ada_2005 and then Old_S /= Any_Id and then not Is_Dispatching_Operation (Old_S) and then Is_Dispatching_Operation (New_S) then declare Old_F : Entity_Id; New_F : Entity_Id; begin Old_F := First_Formal (Old_S); New_F := First_Formal (New_S); while Present (Old_F) loop if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type and then Is_Controlling_Formal (New_F) and then not Can_Never_Be_Null (Old_F) then Error_Msg_N ("access parameter is controlling,", New_F); Error_Msg_NE ("\corresponding parameter of& " & "must be explicitly null excluding", New_F, Old_S); end if; Next_Formal (Old_F); Next_Formal (New_F); end loop; end; end if; -- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005) -- is to warn if an operator is being renamed as a different operator. -- If the operator is predefined, examine the kind of the entity, not -- the abbreviated declaration in Standard. if Comes_From_Source (N) and then Present (Old_S) and then (Nkind (Old_S) = N_Defining_Operator_Symbol or else Ekind (Old_S) = E_Operator) and then Nkind (New_S) = N_Defining_Operator_Symbol and then Chars (Old_S) /= Chars (New_S) then Error_Msg_NE ("?& is being renamed as a different operator", N, Old_S); end if; -- Check for renaming of obsolescent subprogram Check_Obsolescent_2005_Entity (Entity (Nam), Nam); -- Another warning or some utility: if the new subprogram as the same -- name as the old one, the old one is not hidden by an outer homograph, -- the new one is not a public symbol, and the old one is otherwise -- directly visible, the renaming is superfluous. if Chars (Old_S) = Chars (New_S) and then Comes_From_Source (N) and then Scope (Old_S) /= Standard_Standard and then Warn_On_Redundant_Constructs and then (Is_Immediately_Visible (Old_S) or else Is_Potentially_Use_Visible (Old_S)) and then Is_Overloadable (Current_Scope) and then Chars (Current_Scope) /= Chars (Old_S) then Error_Msg_N ("?redundant renaming, entity is directly visible", Name (N)); end if; -- Implementation-defined aspect specifications can appear in a renaming -- declaration, but not language-defined ones. The call to procedure -- Analyze_Aspect_Specifications will take care of this error check. if Has_Aspects (N) then Analyze_Aspect_Specifications (N, New_S); end if; Ada_Version := Save_AV; Ada_Version_Explicit := Save_AV_Exp; end Analyze_Subprogram_Renaming; ------------------------- -- Analyze_Use_Package -- ------------------------- -- Resolve the package names in the use clause, and make all the visible -- entities defined in the package potentially use-visible. If the package -- is already in use from a previous use clause, its visible entities are -- already use-visible. In that case, mark the occurrence as a redundant -- use. If the package is an open scope, i.e. if the use clause occurs -- within the package itself, ignore it. procedure Analyze_Use_Package (N : Node_Id) is Pack_Name : Node_Id; Pack : Entity_Id; -- Start of processing for Analyze_Use_Package begin Check_SPARK_Restriction ("use clause is not allowed", N); Set_Hidden_By_Use_Clause (N, No_Elist); -- Use clause not allowed in a spec of a predefined package declaration -- except that packages whose file name starts a-n are OK (these are -- children of Ada.Numerics, which are never loaded by Rtsfind). if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit)) and then Name_Buffer (1 .. 3) /= "a-n" and then Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration then Error_Msg_N ("use clause not allowed in predefined spec", N); end if; -- Chain clause to list of use clauses in current scope if Nkind (Parent (N)) /= N_Compilation_Unit then Chain_Use_Clause (N); end if; -- Loop through package names to identify referenced packages Pack_Name := First (Names (N)); while Present (Pack_Name) loop Analyze (Pack_Name); if Nkind (Parent (N)) = N_Compilation_Unit and then Nkind (Pack_Name) = N_Expanded_Name then declare Pref : Node_Id; begin Pref := Prefix (Pack_Name); while Nkind (Pref) = N_Expanded_Name loop Pref := Prefix (Pref); end loop; if Entity (Pref) = Standard_Standard then Error_Msg_N ("predefined package Standard cannot appear" & " in a context clause", Pref); end if; end; end if; Next (Pack_Name); end loop; -- Loop through package names to mark all entities as potentially -- use visible. Pack_Name := First (Names (N)); while Present (Pack_Name) loop if Is_Entity_Name (Pack_Name) then Pack := Entity (Pack_Name); if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then if Ekind (Pack) = E_Generic_Package then Error_Msg_N -- CODEFIX ("a generic package is not allowed in a use clause", Pack_Name); else Error_Msg_N ("& is not a usable package", Pack_Name); end if; else if Nkind (Parent (N)) = N_Compilation_Unit then Check_In_Previous_With_Clause (N, Pack_Name); end if; if Applicable_Use (Pack_Name) then Use_One_Package (Pack, N); end if; end if; -- Report error because name denotes something other than a package else Error_Msg_N ("& is not a package", Pack_Name); end if; Next (Pack_Name); end loop; end Analyze_Use_Package; ---------------------- -- Analyze_Use_Type -- ---------------------- procedure Analyze_Use_Type (N : Node_Id) is E : Entity_Id; Id : Node_Id; begin Set_Hidden_By_Use_Clause (N, No_Elist); -- Chain clause to list of use clauses in current scope if Nkind (Parent (N)) /= N_Compilation_Unit then Chain_Use_Clause (N); end if; -- If the Used_Operations list is already initialized, the clause has -- been analyzed previously, and it is begin reinstalled, for example -- when the clause appears in a package spec and we are compiling the -- corresponding package body. In that case, make the entities on the -- existing list use_visible, and mark the corresponding types In_Use. if Present (Used_Operations (N)) then declare Mark : Node_Id; Elmt : Elmt_Id; begin Mark := First (Subtype_Marks (N)); while Present (Mark) loop Use_One_Type (Mark, Installed => True); Next (Mark); end loop; Elmt := First_Elmt (Used_Operations (N)); while Present (Elmt) loop Set_Is_Potentially_Use_Visible (Node (Elmt)); Next_Elmt (Elmt); end loop; end; return; end if; -- Otherwise, create new list and attach to it the operations that -- are made use-visible by the clause. Set_Used_Operations (N, New_Elmt_List); Id := First (Subtype_Marks (N)); while Present (Id) loop Find_Type (Id); E := Entity (Id); if E /= Any_Type then Use_One_Type (Id); if Nkind (Parent (N)) = N_Compilation_Unit then if Nkind (Id) = N_Identifier then Error_Msg_N ("type is not directly visible", Id); elsif Is_Child_Unit (Scope (E)) and then Scope (E) /= System_Aux_Id then Check_In_Previous_With_Clause (N, Prefix (Id)); end if; end if; else -- If the use_type_clause appears in a compilation unit context, -- check whether it comes from a unit that may appear in a -- limited_with_clause, for a better error message. if Nkind (Parent (N)) = N_Compilation_Unit and then Nkind (Id) /= N_Identifier then declare Item : Node_Id; Pref : Node_Id; function Mentioned (Nam : Node_Id) return Boolean; -- Check whether the prefix of expanded name for the type -- appears in the prefix of some limited_with_clause. --------------- -- Mentioned -- --------------- function Mentioned (Nam : Node_Id) return Boolean is begin return Nkind (Name (Item)) = N_Selected_Component and then Chars (Prefix (Name (Item))) = Chars (Nam); end Mentioned; begin Pref := Prefix (Id); Item := First (Context_Items (Parent (N))); while Present (Item) and then Item /= N loop if Nkind (Item) = N_With_Clause and then Limited_Present (Item) and then Mentioned (Pref) then Change_Error_Text (Get_Msg_Id, "premature usage of incomplete type"); end if; Next (Item); end loop; end; end if; end if; Next (Id); end loop; end Analyze_Use_Type; -------------------- -- Applicable_Use -- -------------------- function Applicable_Use (Pack_Name : Node_Id) return Boolean is Pack : constant Entity_Id := Entity (Pack_Name); begin if In_Open_Scopes (Pack) then if Warn_On_Redundant_Constructs and then Pack = Current_Scope then Error_Msg_NE -- CODEFIX ("& is already use-visible within itself?", Pack_Name, Pack); end if; return False; elsif In_Use (Pack) then Note_Redundant_Use (Pack_Name); return False; elsif Present (Renamed_Object (Pack)) and then In_Use (Renamed_Object (Pack)) then Note_Redundant_Use (Pack_Name); return False; else return True; end if; end Applicable_Use; ------------------------ -- Attribute_Renaming -- ------------------------ procedure Attribute_Renaming (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Nam : constant Node_Id := Name (N); Spec : constant Node_Id := Specification (N); New_S : constant Entity_Id := Defining_Unit_Name (Spec); Aname : constant Name_Id := Attribute_Name (Nam); Form_Num : Nat := 0; Expr_List : List_Id := No_List; Attr_Node : Node_Id; Body_Node : Node_Id; Param_Spec : Node_Id; begin Generate_Definition (New_S); -- This procedure is called in the context of subprogram renaming, and -- thus the attribute must be one that is a subprogram. All of those -- have at least one formal parameter, with the singular exception of -- AST_Entry (which is a real oddity, it is odd that this can be renamed -- at all!) if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then if Aname /= Name_AST_Entry then Error_Msg_N ("subprogram renaming an attribute must have formals", N); return; end if; else Param_Spec := First (Parameter_Specifications (Spec)); while Present (Param_Spec) loop Form_Num := Form_Num + 1; if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then Find_Type (Parameter_Type (Param_Spec)); -- The profile of the new entity denotes the base type (s) of -- the types given in the specification. For access parameters -- there are no subtypes involved. Rewrite (Parameter_Type (Param_Spec), New_Reference_To (Base_Type (Entity (Parameter_Type (Param_Spec))), Loc)); end if; if No (Expr_List) then Expr_List := New_List; end if; Append_To (Expr_List, Make_Identifier (Loc, Chars => Chars (Defining_Identifier (Param_Spec)))); -- The expressions in the attribute reference are not freeze -- points. Neither is the attribute as a whole, see below. Set_Must_Not_Freeze (Last (Expr_List)); Next (Param_Spec); end loop; end if; -- Immediate error if too many formals. Other mismatches in number or -- types of parameters are detected when we analyze the body of the -- subprogram that we construct. if Form_Num > 2 then Error_Msg_N ("too many formals for attribute", N); -- Error if the attribute reference has expressions that look like -- formal parameters. elsif Present (Expressions (Nam)) then Error_Msg_N ("illegal expressions in attribute reference", Nam); elsif Aname = Name_Compose or else Aname = Name_Exponent or else Aname = Name_Leading_Part or else Aname = Name_Pos or else Aname = Name_Round or else Aname = Name_Scaling or else Aname = Name_Val then if Nkind (N) = N_Subprogram_Renaming_Declaration and then Present (Corresponding_Formal_Spec (N)) then Error_Msg_N ("generic actual cannot be attribute involving universal type", Nam); else Error_Msg_N ("attribute involving a universal type cannot be renamed", Nam); end if; end if; -- AST_Entry is an odd case. It doesn't really make much sense to allow -- it to be renamed, but that's the DEC rule, so we have to do it right. -- The point is that the AST_Entry call should be made now, and what the -- function will return is the returned value. -- Note that there is no Expr_List in this case anyway if Aname = Name_AST_Entry then declare Ent : constant Entity_Id := Make_Temporary (Loc, 'R', Nam); Decl : Node_Id; begin Decl := Make_Object_Declaration (Loc, Defining_Identifier => Ent, Object_Definition => New_Occurrence_Of (RTE (RE_AST_Handler), Loc), Expression => Nam, Constant_Present => True); Set_Assignment_OK (Decl, True); Insert_Action (N, Decl); Attr_Node := Make_Identifier (Loc, Chars (Ent)); end; -- For all other attributes, we rewrite the attribute node to have -- a list of expressions corresponding to the subprogram formals. -- A renaming declaration is not a freeze point, and the analysis of -- the attribute reference should not freeze the type of the prefix. else Attr_Node := Make_Attribute_Reference (Loc, Prefix => Prefix (Nam), Attribute_Name => Aname, Expressions => Expr_List); Set_Must_Not_Freeze (Attr_Node); Set_Must_Not_Freeze (Prefix (Nam)); end if; -- Case of renaming a function if Nkind (Spec) = N_Function_Specification then if Is_Procedure_Attribute_Name (Aname) then Error_Msg_N ("attribute can only be renamed as procedure", Nam); return; end if; Find_Type (Result_Definition (Spec)); Rewrite (Result_Definition (Spec), New_Reference_To ( Base_Type (Entity (Result_Definition (Spec))), Loc)); Body_Node := Make_Subprogram_Body (Loc, Specification => Spec, Declarations => New_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List ( Make_Simple_Return_Statement (Loc, Expression => Attr_Node)))); -- Case of renaming a procedure else if not Is_Procedure_Attribute_Name (Aname) then Error_Msg_N ("attribute can only be renamed as function", Nam); return; end if; Body_Node := Make_Subprogram_Body (Loc, Specification => Spec, Declarations => New_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List (Attr_Node))); end if; -- In case of tagged types we add the body of the generated function to -- the freezing actions of the type (because in the general case such -- type is still not frozen). We exclude from this processing generic -- formal subprograms found in instantiations and AST_Entry renamings. -- We must exclude VM targets and restricted run-time libraries because -- entity AST_Handler is defined in package System.Aux_Dec which is not -- available in those platforms. Note that we cannot use the function -- Restricted_Profile (instead of Configurable_Run_Time_Mode) because -- the ZFP run-time library is not defined as a profile, and we do not -- want to deal with AST_Handler in ZFP mode. if VM_Target = No_VM and then not Configurable_Run_Time_Mode and then not Present (Corresponding_Formal_Spec (N)) and then Etype (Nam) /= RTE (RE_AST_Handler) then declare P : constant Entity_Id := Prefix (Nam); begin Find_Type (P); if Is_Tagged_Type (Etype (P)) then Ensure_Freeze_Node (Etype (P)); Append_Freeze_Action (Etype (P), Body_Node); else Rewrite (N, Body_Node); Analyze (N); Set_Etype (New_S, Base_Type (Etype (New_S))); end if; end; -- Generic formal subprograms or AST_Handler renaming else Rewrite (N, Body_Node); Analyze (N); Set_Etype (New_S, Base_Type (Etype (New_S))); end if; if Is_Compilation_Unit (New_S) then Error_Msg_N ("a library unit can only rename another library unit", N); end if; -- We suppress elaboration warnings for the resulting entity, since -- clearly they are not needed, and more particularly, in the case -- of a generic formal subprogram, the resulting entity can appear -- after the instantiation itself, and thus look like a bogus case -- of access before elaboration. Set_Suppress_Elaboration_Warnings (New_S); end Attribute_Renaming; ---------------------- -- Chain_Use_Clause -- ---------------------- procedure Chain_Use_Clause (N : Node_Id) is Pack : Entity_Id; Level : Int := Scope_Stack.Last; begin if not Is_Compilation_Unit (Current_Scope) or else not Is_Child_Unit (Current_Scope) then null; -- Common case elsif Defining_Entity (Parent (N)) = Current_Scope then null; -- Common case for compilation unit else -- If declaration appears in some other scope, it must be in some -- parent unit when compiling a child. Pack := Defining_Entity (Parent (N)); if not In_Open_Scopes (Pack) then null; -- default as well else -- Find entry for parent unit in scope stack while Scope_Stack.Table (Level).Entity /= Pack loop Level := Level - 1; end loop; end if; end if; Set_Next_Use_Clause (N, Scope_Stack.Table (Level).First_Use_Clause); Scope_Stack.Table (Level).First_Use_Clause := N; end Chain_Use_Clause; --------------------------- -- Check_Frozen_Renaming -- --------------------------- procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is B_Node : Node_Id; Old_S : Entity_Id; begin if Is_Frozen (Subp) and then not Has_Completion (Subp) then B_Node := Build_Renamed_Body (Parent (Declaration_Node (Subp)), Defining_Entity (N)); if Is_Entity_Name (Name (N)) then Old_S := Entity (Name (N)); if not Is_Frozen (Old_S) and then Operating_Mode /= Check_Semantics then Append_Freeze_Action (Old_S, B_Node); else Insert_After (N, B_Node); Analyze (B_Node); end if; if Is_Intrinsic_Subprogram (Old_S) and then not In_Instance then Error_Msg_N ("subprogram used in renaming_as_body cannot be intrinsic", Name (N)); end if; else Insert_After (N, B_Node); Analyze (B_Node); end if; end if; end Check_Frozen_Renaming; ------------------------------- -- Set_Entity_Or_Discriminal -- ------------------------------- procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is P : Node_Id; begin -- If the entity is not a discriminant, or else expansion is disabled, -- simply set the entity. if not In_Spec_Expression or else Ekind (E) /= E_Discriminant or else Inside_A_Generic then Set_Entity_With_Style_Check (N, E); -- The replacement of a discriminant by the corresponding discriminal -- is not done for a task discriminant that appears in a default -- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant -- for details on their handling. elsif Is_Concurrent_Type (Scope (E)) then P := Parent (N); while Present (P) and then not Nkind_In (P, N_Parameter_Specification, N_Component_Declaration) loop P := Parent (P); end loop; if Present (P) and then Nkind (P) = N_Parameter_Specification then null; else Set_Entity (N, Discriminal (E)); end if; -- Otherwise, this is a discriminant in a context in which -- it is a reference to the corresponding parameter of the -- init proc for the enclosing type. else Set_Entity (N, Discriminal (E)); end if; end Set_Entity_Or_Discriminal; ----------------------------------- -- Check_In_Previous_With_Clause -- ----------------------------------- procedure Check_In_Previous_With_Clause (N : Node_Id; Nam : Entity_Id) is Pack : constant Entity_Id := Entity (Original_Node (Nam)); Item : Node_Id; Par : Node_Id; begin Item := First (Context_Items (Parent (N))); while Present (Item) and then Item /= N loop if Nkind (Item) = N_With_Clause -- Protect the frontend against previous critical errors and then Nkind (Name (Item)) /= N_Selected_Component and then Entity (Name (Item)) = Pack then Par := Nam; -- Find root library unit in with_clause while Nkind (Par) = N_Expanded_Name loop Par := Prefix (Par); end loop; if Is_Child_Unit (Entity (Original_Node (Par))) then Error_Msg_NE ("& is not directly visible", Par, Entity (Par)); else return; end if; end if; Next (Item); end loop; -- On exit, package is not mentioned in a previous with_clause. -- Check if its prefix is. if Nkind (Nam) = N_Expanded_Name then Check_In_Previous_With_Clause (N, Prefix (Nam)); elsif Pack /= Any_Id then Error_Msg_NE ("& is not visible", Nam, Pack); end if; end Check_In_Previous_With_Clause; --------------------------------- -- Check_Library_Unit_Renaming -- --------------------------------- procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is New_E : Entity_Id; begin if Nkind (Parent (N)) /= N_Compilation_Unit then return; -- Check for library unit. Note that we used to check for the scope -- being Standard here, but that was wrong for Standard itself. elsif not Is_Compilation_Unit (Old_E) and then not Is_Child_Unit (Old_E) then Error_Msg_N ("renamed unit must be a library unit", Name (N)); -- Entities defined in Standard (operators and boolean literals) cannot -- be renamed as library units. elsif Scope (Old_E) = Standard_Standard and then Sloc (Old_E) = Standard_Location then Error_Msg_N ("renamed unit must be a library unit", Name (N)); elsif Present (Parent_Spec (N)) and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration and then not Is_Child_Unit (Old_E) then Error_Msg_N ("renamed unit must be a child unit of generic parent", Name (N)); elsif Nkind (N) in N_Generic_Renaming_Declaration and then Nkind (Name (N)) = N_Expanded_Name and then Is_Generic_Instance (Entity (Prefix (Name (N)))) and then Is_Generic_Unit (Old_E) then Error_Msg_N ("renamed generic unit must be a library unit", Name (N)); elsif Is_Package_Or_Generic_Package (Old_E) then -- Inherit categorization flags New_E := Defining_Entity (N); Set_Is_Pure (New_E, Is_Pure (Old_E)); Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E)); Set_Is_Remote_Call_Interface (New_E, Is_Remote_Call_Interface (Old_E)); Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E)); Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E)); end if; end Check_Library_Unit_Renaming; --------------- -- End_Scope -- --------------- procedure End_Scope is Id : Entity_Id; Prev : Entity_Id; Outer : Entity_Id; begin Id := First_Entity (Current_Scope); while Present (Id) loop -- An entity in the current scope is not necessarily the first one -- on its homonym chain. Find its predecessor if any, -- If it is an internal entity, it will not be in the visibility -- chain altogether, and there is nothing to unchain. if Id /= Current_Entity (Id) then Prev := Current_Entity (Id); while Present (Prev) and then Present (Homonym (Prev)) and then Homonym (Prev) /= Id loop Prev := Homonym (Prev); end loop; -- Skip to end of loop if Id is not in the visibility chain if No (Prev) or else Homonym (Prev) /= Id then goto Next_Ent; end if; else Prev := Empty; end if; Set_Is_Immediately_Visible (Id, False); Outer := Homonym (Id); while Present (Outer) and then Scope (Outer) = Current_Scope loop Outer := Homonym (Outer); end loop; -- Reset homonym link of other entities, but do not modify link -- between entities in current scope, so that the back-end can have -- a proper count of local overloadings. if No (Prev) then Set_Name_Entity_Id (Chars (Id), Outer); elsif Scope (Prev) /= Scope (Id) then Set_Homonym (Prev, Outer); end if; <<Next_Ent>> Next_Entity (Id); end loop; -- If the scope generated freeze actions, place them before the -- current declaration and analyze them. Type declarations and -- the bodies of initialization procedures can generate such nodes. -- We follow the parent chain until we reach a list node, which is -- the enclosing list of declarations. If the list appears within -- a protected definition, move freeze nodes outside the protected -- type altogether. if Present (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions) then declare Decl : Node_Id; L : constant List_Id := Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions; begin if Is_Itype (Current_Scope) then Decl := Associated_Node_For_Itype (Current_Scope); else Decl := Parent (Current_Scope); end if; Pop_Scope; while not (Is_List_Member (Decl)) or else Nkind_In (Parent (Decl), N_Protected_Definition, N_Task_Definition) loop Decl := Parent (Decl); end loop; Insert_List_Before_And_Analyze (Decl, L); end; else Pop_Scope; end if; end End_Scope; --------------------- -- End_Use_Clauses -- --------------------- procedure End_Use_Clauses (Clause : Node_Id) is U : Node_Id; begin -- Remove Use_Type clauses first, because they affect the -- visibility of operators in subsequent used packages. U := Clause; while Present (U) loop if Nkind (U) = N_Use_Type_Clause then End_Use_Type (U); end if; Next_Use_Clause (U); end loop; U := Clause; while Present (U) loop if Nkind (U) = N_Use_Package_Clause then End_Use_Package (U); end if; Next_Use_Clause (U); end loop; end End_Use_Clauses; --------------------- -- End_Use_Package -- --------------------- procedure End_Use_Package (N : Node_Id) is Pack_Name : Node_Id; Pack : Entity_Id; Id : Entity_Id; Elmt : Elmt_Id; function Is_Primitive_Operator_In_Use (Op : Entity_Id; F : Entity_Id) return Boolean; -- Check whether Op is a primitive operator of a use-visible type ---------------------------------- -- Is_Primitive_Operator_In_Use -- ---------------------------------- function Is_Primitive_Operator_In_Use (Op : Entity_Id; F : Entity_Id) return Boolean is T : constant Entity_Id := Base_Type (Etype (F)); begin return In_Use (T) and then Scope (T) = Scope (Op); end Is_Primitive_Operator_In_Use; -- Start of processing for End_Use_Package begin Pack_Name := First (Names (N)); while Present (Pack_Name) loop -- Test that Pack_Name actually denotes a package before processing if Is_Entity_Name (Pack_Name) and then Ekind (Entity (Pack_Name)) = E_Package then Pack := Entity (Pack_Name); if In_Open_Scopes (Pack) then null; elsif not Redundant_Use (Pack_Name) then Set_In_Use (Pack, False); Set_Current_Use_Clause (Pack, Empty); Id := First_Entity (Pack); while Present (Id) loop -- Preserve use-visibility of operators that are primitive -- operators of a type that is use-visible through an active -- use_type clause. if Nkind (Id) = N_Defining_Operator_Symbol and then (Is_Primitive_Operator_In_Use (Id, First_Formal (Id)) or else (Present (Next_Formal (First_Formal (Id))) and then Is_Primitive_Operator_In_Use (Id, Next_Formal (First_Formal (Id))))) then null; else Set_Is_Potentially_Use_Visible (Id, False); end if; if Is_Private_Type (Id) and then Present (Full_View (Id)) then Set_Is_Potentially_Use_Visible (Full_View (Id), False); end if; Next_Entity (Id); end loop; if Present (Renamed_Object (Pack)) then Set_In_Use (Renamed_Object (Pack), False); Set_Current_Use_Clause (Renamed_Object (Pack), Empty); end if; if Chars (Pack) = Name_System and then Scope (Pack) = Standard_Standard and then Present_System_Aux then Id := First_Entity (System_Aux_Id); while Present (Id) loop Set_Is_Potentially_Use_Visible (Id, False); if Is_Private_Type (Id) and then Present (Full_View (Id)) then Set_Is_Potentially_Use_Visible (Full_View (Id), False); end if; Next_Entity (Id); end loop; Set_In_Use (System_Aux_Id, False); end if; else Set_Redundant_Use (Pack_Name, False); end if; end if; Next (Pack_Name); end loop; if Present (Hidden_By_Use_Clause (N)) then Elmt := First_Elmt (Hidden_By_Use_Clause (N)); while Present (Elmt) loop declare E : constant Entity_Id := Node (Elmt); begin -- Reset either Use_Visibility or Direct_Visibility, depending -- on how the entity was hidden by the use clause. if In_Use (Scope (E)) and then Used_As_Generic_Actual (Scope (E)) then Set_Is_Potentially_Use_Visible (Node (Elmt)); else Set_Is_Immediately_Visible (Node (Elmt)); end if; Next_Elmt (Elmt); end; end loop; Set_Hidden_By_Use_Clause (N, No_Elist); end if; end End_Use_Package; ------------------ -- End_Use_Type -- ------------------ procedure End_Use_Type (N : Node_Id) is Elmt : Elmt_Id; Id : Entity_Id; T : Entity_Id; -- Start of processing for End_Use_Type begin Id := First (Subtype_Marks (N)); while Present (Id) loop -- A call to Rtsfind may occur while analyzing a use_type clause, -- in which case the type marks are not resolved yet, and there is -- nothing to remove. if not Is_Entity_Name (Id) or else No (Entity (Id)) then goto Continue; end if; T := Entity (Id); if T = Any_Type or else From_With_Type (T) then null; -- Note that the use_type clause may mention a subtype of the type -- whose primitive operations have been made visible. Here as -- elsewhere, it is the base type that matters for visibility. elsif In_Open_Scopes (Scope (Base_Type (T))) then null; elsif not Redundant_Use (Id) then Set_In_Use (T, False); Set_In_Use (Base_Type (T), False); Set_Current_Use_Clause (T, Empty); Set_Current_Use_Clause (Base_Type (T), Empty); end if; <<Continue>> Next (Id); end loop; if Is_Empty_Elmt_List (Used_Operations (N)) then return; else Elmt := First_Elmt (Used_Operations (N)); while Present (Elmt) loop Set_Is_Potentially_Use_Visible (Node (Elmt), False); Next_Elmt (Elmt); end loop; end if; end End_Use_Type; ---------------------- -- Find_Direct_Name -- ---------------------- procedure Find_Direct_Name (N : Node_Id) is E : Entity_Id; E2 : Entity_Id; Msg : Boolean; Inst : Entity_Id := Empty; -- Enclosing instance, if any Homonyms : Entity_Id; -- Saves start of homonym chain Nvis_Entity : Boolean; -- Set True to indicate that there is at least one entity on the homonym -- chain which, while not visible, is visible enough from the user point -- of view to warrant an error message of "not visible" rather than -- undefined. Nvis_Is_Private_Subprg : Boolean := False; -- Ada 2005 (AI-262): Set True to indicate that a form of Beaujolais -- effect concerning library subprograms has been detected. Used to -- generate the precise error message. function From_Actual_Package (E : Entity_Id) return Boolean; -- Returns true if the entity is declared in a package that is -- an actual for a formal package of the current instance. Such an -- entity requires special handling because it may be use-visible -- but hides directly visible entities defined outside the instance. function Is_Actual_Parameter return Boolean; -- This function checks if the node N is an identifier that is an actual -- parameter of a procedure call. If so it returns True, otherwise it -- return False. The reason for this check is that at this stage we do -- not know what procedure is being called if the procedure might be -- overloaded, so it is premature to go setting referenced flags or -- making calls to Generate_Reference. We will wait till Resolve_Actuals -- for that processing function Known_But_Invisible (E : Entity_Id) return Boolean; -- This function determines whether the entity E (which is not -- visible) can reasonably be considered to be known to the writer -- of the reference. This is a heuristic test, used only for the -- purposes of figuring out whether we prefer to complain that an -- entity is undefined or invisible (and identify the declaration -- of the invisible entity in the latter case). The point here is -- that we don't want to complain that something is invisible and -- then point to something entirely mysterious to the writer. procedure Nvis_Messages; -- Called if there are no visible entries for N, but there is at least -- one non-directly visible, or hidden declaration. This procedure -- outputs an appropriate set of error messages. procedure Undefined (Nvis : Boolean); -- This function is called if the current node has no corresponding -- visible entity or entities. The value set in Msg indicates whether -- an error message was generated (multiple error messages for the -- same variable are generally suppressed, see body for details). -- Msg is True if an error message was generated, False if not. This -- value is used by the caller to determine whether or not to output -- additional messages where appropriate. The parameter is set False -- to get the message "X is undefined", and True to get the message -- "X is not visible". ------------------------- -- From_Actual_Package -- ------------------------- function From_Actual_Package (E : Entity_Id) return Boolean is Scop : constant Entity_Id := Scope (E); Act : Entity_Id; begin if not In_Instance then return False; else Inst := Current_Scope; while Present (Inst) and then Ekind (Inst) /= E_Package and then not Is_Generic_Instance (Inst) loop Inst := Scope (Inst); end loop; if No (Inst) then return False; end if; Act := First_Entity (Inst); while Present (Act) loop if Ekind (Act) = E_Package then -- Check for end of actuals list if Renamed_Object (Act) = Inst then return False; elsif Present (Associated_Formal_Package (Act)) and then Renamed_Object (Act) = Scop then -- Entity comes from (instance of) formal package return True; else Next_Entity (Act); end if; else Next_Entity (Act); end if; end loop; return False; end if; end From_Actual_Package; ------------------------- -- Is_Actual_Parameter -- ------------------------- function Is_Actual_Parameter return Boolean is begin return Nkind (N) = N_Identifier and then (Nkind (Parent (N)) = N_Procedure_Call_Statement or else (Nkind (Parent (N)) = N_Parameter_Association and then N = Explicit_Actual_Parameter (Parent (N)) and then Nkind (Parent (Parent (N))) = N_Procedure_Call_Statement)); end Is_Actual_Parameter; ------------------------- -- Known_But_Invisible -- ------------------------- function Known_But_Invisible (E : Entity_Id) return Boolean is Fname : File_Name_Type; begin -- Entities in Standard are always considered to be known if Sloc (E) <= Standard_Location then return True; -- An entity that does not come from source is always considered -- to be unknown, since it is an artifact of code expansion. elsif not Comes_From_Source (E) then return False; -- In gnat internal mode, we consider all entities known elsif GNAT_Mode then return True; end if; -- Here we have an entity that is not from package Standard, and -- which comes from Source. See if it comes from an internal file. Fname := Unit_File_Name (Get_Source_Unit (E)); -- Case of from internal file if Is_Internal_File_Name (Fname) then -- Private part entities in internal files are never considered -- to be known to the writer of normal application code. if Is_Hidden (E) then return False; end if; -- Entities from System packages other than System and -- System.Storage_Elements are not considered to be known. -- System.Auxxxx files are also considered known to the user. -- Should refine this at some point to generally distinguish -- between known and unknown internal files ??? Get_Name_String (Fname); return Name_Len < 2 or else Name_Buffer (1 .. 2) /= "s-" or else Name_Buffer (3 .. 8) = "stoele" or else Name_Buffer (3 .. 5) = "aux"; -- If not an internal file, then entity is definitely known, -- even if it is in a private part (the message generated will -- note that it is in a private part) else return True; end if; end Known_But_Invisible; ------------------- -- Nvis_Messages -- ------------------- procedure Nvis_Messages is Comp_Unit : Node_Id; Ent : Entity_Id; Found : Boolean := False; Hidden : Boolean := False; Item : Node_Id; begin -- Ada 2005 (AI-262): Generate a precise error concerning the -- Beaujolais effect that was previously detected if Nvis_Is_Private_Subprg then pragma Assert (Nkind (E2) = N_Defining_Identifier and then Ekind (E2) = E_Function and then Scope (E2) = Standard_Standard and then Has_Private_With (E2)); -- Find the sloc corresponding to the private with'ed unit Comp_Unit := Cunit (Current_Sem_Unit); Error_Msg_Sloc := No_Location; Item := First (Context_Items (Comp_Unit)); while Present (Item) loop if Nkind (Item) = N_With_Clause and then Private_Present (Item) and then Entity (Name (Item)) = E2 then Error_Msg_Sloc := Sloc (Item); exit; end if; Next (Item); end loop; pragma Assert (Error_Msg_Sloc /= No_Location); Error_Msg_N ("(Ada 2005): hidden by private with clause #", N); return; end if; Undefined (Nvis => True); if Msg then -- First loop does hidden declarations Ent := Homonyms; while Present (Ent) loop if Is_Potentially_Use_Visible (Ent) then if not Hidden then Error_Msg_N -- CODEFIX ("multiple use clauses cause hiding!", N); Hidden := True; end if; Error_Msg_Sloc := Sloc (Ent); Error_Msg_N -- CODEFIX ("hidden declaration#!", N); end if; Ent := Homonym (Ent); end loop; -- If we found hidden declarations, then that's enough, don't -- bother looking for non-visible declarations as well. if Hidden then return; end if; -- Second loop does non-directly visible declarations Ent := Homonyms; while Present (Ent) loop if not Is_Potentially_Use_Visible (Ent) then -- Do not bother the user with unknown entities if not Known_But_Invisible (Ent) then goto Continue; end if; Error_Msg_Sloc := Sloc (Ent); -- Output message noting that there is a non-visible -- declaration, distinguishing the private part case. if Is_Hidden (Ent) then Error_Msg_N ("non-visible (private) declaration#!", N); -- If the entity is declared in a generic package, it -- cannot be visible, so there is no point in adding it -- to the list of candidates if another homograph from a -- non-generic package has been seen. elsif Ekind (Scope (Ent)) = E_Generic_Package and then Found then null; else Error_Msg_N -- CODEFIX ("non-visible declaration#!", N); if Ekind (Scope (Ent)) /= E_Generic_Package then Found := True; end if; if Is_Compilation_Unit (Ent) and then Nkind (Parent (Parent (N))) = N_Use_Package_Clause then Error_Msg_Qual_Level := 99; Error_Msg_NE -- CODEFIX ("\\missing `WITH &;`", N, Ent); Error_Msg_Qual_Level := 0; end if; if Ekind (Ent) = E_Discriminant and then Present (Corresponding_Discriminant (Ent)) and then Scope (Corresponding_Discriminant (Ent)) = Etype (Scope (Ent)) then Error_Msg_N ("inherited discriminant not allowed here" & " (RM 3.8 (12), 3.8.1 (6))!", N); end if; end if; -- Set entity and its containing package as referenced. We -- can't be sure of this, but this seems a better choice -- to avoid unused entity messages. if Comes_From_Source (Ent) then Set_Referenced (Ent); Set_Referenced (Cunit_Entity (Get_Source_Unit (Ent))); end if; end if; <<Continue>> Ent := Homonym (Ent); end loop; end if; end Nvis_Messages; --------------- -- Undefined -- --------------- procedure Undefined (Nvis : Boolean) is Emsg : Error_Msg_Id; begin -- We should never find an undefined internal name. If we do, then -- see if we have previous errors. If so, ignore on the grounds that -- it is probably a cascaded message (e.g. a block label from a badly -- formed block). If no previous errors, then we have a real internal -- error of some kind so raise an exception. if Is_Internal_Name (Chars (N)) then if Total_Errors_Detected /= 0 then return; else raise Program_Error; end if; end if; -- A very specialized error check, if the undefined variable is -- a case tag, and the case type is an enumeration type, check -- for a possible misspelling, and if so, modify the identifier -- Named aggregate should also be handled similarly ??? if Nkind (N) = N_Identifier and then Nkind (Parent (N)) = N_Case_Statement_Alternative then declare Case_Stm : constant Node_Id := Parent (Parent (N)); Case_Typ : constant Entity_Id := Etype (Expression (Case_Stm)); Lit : Node_Id; begin if Is_Enumeration_Type (Case_Typ) and then not Is_Standard_Character_Type (Case_Typ) then Lit := First_Literal (Case_Typ); Get_Name_String (Chars (Lit)); if Chars (Lit) /= Chars (N) and then Is_Bad_Spelling_Of (Chars (N), Chars (Lit)) then Error_Msg_Node_2 := Lit; Error_Msg_N -- CODEFIX ("& is undefined, assume misspelling of &", N); Rewrite (N, New_Occurrence_Of (Lit, Sloc (N))); return; end if; Lit := Next_Literal (Lit); end if; end; end if; -- Normal processing Set_Entity (N, Any_Id); Set_Etype (N, Any_Type); -- We use the table Urefs to keep track of entities for which we -- have issued errors for undefined references. Multiple errors -- for a single name are normally suppressed, however we modify -- the error message to alert the programmer to this effect. for J in Urefs.First .. Urefs.Last loop if Chars (N) = Chars (Urefs.Table (J).Node) then if Urefs.Table (J).Err /= No_Error_Msg and then Sloc (N) /= Urefs.Table (J).Loc then Error_Msg_Node_1 := Urefs.Table (J).Node; if Urefs.Table (J).Nvis then Change_Error_Text (Urefs.Table (J).Err, "& is not visible (more references follow)"); else Change_Error_Text (Urefs.Table (J).Err, "& is undefined (more references follow)"); end if; Urefs.Table (J).Err := No_Error_Msg; end if; -- Although we will set Msg False, and thus suppress the -- message, we also set Error_Posted True, to avoid any -- cascaded messages resulting from the undefined reference. Msg := False; Set_Error_Posted (N, True); return; end if; end loop; -- If entry not found, this is first undefined occurrence if Nvis then Error_Msg_N ("& is not visible!", N); Emsg := Get_Msg_Id; else Error_Msg_N ("& is undefined!", N); Emsg := Get_Msg_Id; -- A very bizarre special check, if the undefined identifier -- is put or put_line, then add a special error message (since -- this is a very common error for beginners to make). if Chars (N) = Name_Put or else Chars (N) = Name_Put_Line then Error_Msg_N -- CODEFIX ("\\possible missing `WITH Ada.Text_'I'O; " & "USE Ada.Text_'I'O`!", N); -- Another special check if N is the prefix of a selected -- component which is a known unit, add message complaining -- about missing with for this unit. elsif Nkind (Parent (N)) = N_Selected_Component and then N = Prefix (Parent (N)) and then Is_Known_Unit (Parent (N)) then Error_Msg_Node_2 := Selector_Name (Parent (N)); Error_Msg_N -- CODEFIX ("\\missing `WITH &.&;`", Prefix (Parent (N))); end if; -- Now check for possible misspellings declare E : Entity_Id; Ematch : Entity_Id := Empty; Last_Name_Id : constant Name_Id := Name_Id (Nat (First_Name_Id) + Name_Entries_Count - 1); begin for Nam in First_Name_Id .. Last_Name_Id loop E := Get_Name_Entity_Id (Nam); if Present (E) and then (Is_Immediately_Visible (E) or else Is_Potentially_Use_Visible (E)) then if Is_Bad_Spelling_Of (Chars (N), Nam) then Ematch := E; exit; end if; end if; end loop; if Present (Ematch) then Error_Msg_NE -- CODEFIX ("\possible misspelling of&", N, Ematch); end if; end; end if; -- Make entry in undefined references table unless the full errors -- switch is set, in which case by refraining from generating the -- table entry, we guarantee that we get an error message for every -- undefined reference. if not All_Errors_Mode then Urefs.Append ( (Node => N, Err => Emsg, Nvis => Nvis, Loc => Sloc (N))); end if; Msg := True; end Undefined; -- Start of processing for Find_Direct_Name begin -- If the entity pointer is already set, this is an internal node, or -- a node that is analyzed more than once, after a tree modification. -- In such a case there is no resolution to perform, just set the type. if Present (Entity (N)) then if Is_Type (Entity (N)) then Set_Etype (N, Entity (N)); else declare Entyp : constant Entity_Id := Etype (Entity (N)); begin -- One special case here. If the Etype field is already set, -- and references the packed array type corresponding to the -- etype of the referenced entity, then leave it alone. This -- happens for trees generated from Exp_Pakd, where expressions -- can be deliberately "mis-typed" to the packed array type. if Is_Array_Type (Entyp) and then Is_Packed (Entyp) and then Present (Etype (N)) and then Etype (N) = Packed_Array_Type (Entyp) then null; -- If not that special case, then just reset the Etype else Set_Etype (N, Etype (Entity (N))); end if; end; end if; return; end if; -- Here if Entity pointer was not set, we need full visibility analysis -- First we generate debugging output if the debug E flag is set. if Debug_Flag_E then Write_Str ("Looking for "); Write_Name (Chars (N)); Write_Eol; end if; Homonyms := Current_Entity (N); Nvis_Entity := False; E := Homonyms; while Present (E) loop -- If entity is immediately visible or potentially use visible, then -- process the entity and we are done. if Is_Immediately_Visible (E) then goto Immediately_Visible_Entity; elsif Is_Potentially_Use_Visible (E) then goto Potentially_Use_Visible_Entity; -- Note if a known but invisible entity encountered elsif Known_But_Invisible (E) then Nvis_Entity := True; end if; -- Move to next entity in chain and continue search E := Homonym (E); end loop; -- If no entries on homonym chain that were potentially visible, -- and no entities reasonably considered as non-visible, then -- we have a plain undefined reference, with no additional -- explanation required! if not Nvis_Entity then Undefined (Nvis => False); -- Otherwise there is at least one entry on the homonym chain that -- is reasonably considered as being known and non-visible. else Nvis_Messages; end if; return; -- Processing for a potentially use visible entry found. We must search -- the rest of the homonym chain for two reasons. First, if there is a -- directly visible entry, then none of the potentially use-visible -- entities are directly visible (RM 8.4(10)). Second, we need to check -- for the case of multiple potentially use-visible entries hiding one -- another and as a result being non-directly visible (RM 8.4(11)). <<Potentially_Use_Visible_Entity>> declare Only_One_Visible : Boolean := True; All_Overloadable : Boolean := Is_Overloadable (E); begin E2 := Homonym (E); while Present (E2) loop if Is_Immediately_Visible (E2) then -- If the use-visible entity comes from the actual for a -- formal package, it hides a directly visible entity from -- outside the instance. if From_Actual_Package (E) and then Scope_Depth (E2) < Scope_Depth (Inst) then goto Found; else E := E2; goto Immediately_Visible_Entity; end if; elsif Is_Potentially_Use_Visible (E2) then Only_One_Visible := False; All_Overloadable := All_Overloadable and Is_Overloadable (E2); -- Ada 2005 (AI-262): Protect against a form of Beaujolais effect -- that can occur in private_with clauses. Example: -- with A; -- private with B; package A is -- package C is function B return Integer; -- use A; end A; -- V1 : Integer := B; -- private function B return Integer; -- V2 : Integer := B; -- end C; -- V1 resolves to A.B, but V2 resolves to library unit B elsif Ekind (E2) = E_Function and then Scope (E2) = Standard_Standard and then Has_Private_With (E2) then Only_One_Visible := False; All_Overloadable := False; Nvis_Is_Private_Subprg := True; exit; end if; E2 := Homonym (E2); end loop; -- On falling through this loop, we have checked that there are no -- immediately visible entities. Only_One_Visible is set if exactly -- one potentially use visible entity exists. All_Overloadable is -- set if all the potentially use visible entities are overloadable. -- The condition for legality is that either there is one potentially -- use visible entity, or if there is more than one, then all of them -- are overloadable. if Only_One_Visible or All_Overloadable then goto Found; -- If there is more than one potentially use-visible entity and at -- least one of them non-overloadable, we have an error (RM 8.4(11). -- Note that E points to the first such entity on the homonym list. -- Special case: if one of the entities is declared in an actual -- package, it was visible in the generic, and takes precedence over -- other entities that are potentially use-visible. Same if it is -- declared in a local instantiation of the current instance. else if In_Instance then -- Find current instance Inst := Current_Scope; while Present (Inst) and then Inst /= Standard_Standard loop if Is_Generic_Instance (Inst) then exit; end if; Inst := Scope (Inst); end loop; E2 := E; while Present (E2) loop if From_Actual_Package (E2) or else (Is_Generic_Instance (Scope (E2)) and then Scope_Depth (Scope (E2)) > Scope_Depth (Inst)) then E := E2; goto Found; end if; E2 := Homonym (E2); end loop; Nvis_Messages; return; elsif Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit)) then -- A use-clause in the body of a system file creates conflict -- with some entity in a user scope, while rtsfind is active. -- Keep only the entity coming from another predefined unit. E2 := E; while Present (E2) loop if Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Sloc (E2)))) then E := E2; goto Found; end if; E2 := Homonym (E2); end loop; -- Entity must exist because predefined unit is correct raise Program_Error; else Nvis_Messages; return; end if; end if; end; -- Come here with E set to the first immediately visible entity on -- the homonym chain. This is the one we want unless there is another -- immediately visible entity further on in the chain for an inner -- scope (RM 8.3(8)). <<Immediately_Visible_Entity>> declare Level : Int; Scop : Entity_Id; begin -- Find scope level of initial entity. When compiling through -- Rtsfind, the previous context is not completely invisible, and -- an outer entity may appear on the chain, whose scope is below -- the entry for Standard that delimits the current scope stack. -- Indicate that the level for this spurious entry is outside of -- the current scope stack. Level := Scope_Stack.Last; loop Scop := Scope_Stack.Table (Level).Entity; exit when Scop = Scope (E); Level := Level - 1; exit when Scop = Standard_Standard; end loop; -- Now search remainder of homonym chain for more inner entry -- If the entity is Standard itself, it has no scope, and we -- compare it with the stack entry directly. E2 := Homonym (E); while Present (E2) loop if Is_Immediately_Visible (E2) then -- If a generic package contains a local declaration that -- has the same name as the generic, there may be a visibility -- conflict in an instance, where the local declaration must -- also hide the name of the corresponding package renaming. -- We check explicitly for a package declared by a renaming, -- whose renamed entity is an instance that is on the scope -- stack, and that contains a homonym in the same scope. Once -- we have found it, we know that the package renaming is not -- immediately visible, and that the identifier denotes the -- other entity (and its homonyms if overloaded). if Scope (E) = Scope (E2) and then Ekind (E) = E_Package and then Present (Renamed_Object (E)) and then Is_Generic_Instance (Renamed_Object (E)) and then In_Open_Scopes (Renamed_Object (E)) and then Comes_From_Source (N) then Set_Is_Immediately_Visible (E, False); E := E2; else for J in Level + 1 .. Scope_Stack.Last loop if Scope_Stack.Table (J).Entity = Scope (E2) or else Scope_Stack.Table (J).Entity = E2 then Level := J; E := E2; exit; end if; end loop; end if; end if; E2 := Homonym (E2); end loop; -- At the end of that loop, E is the innermost immediately -- visible entity, so we are all set. end; -- Come here with entity found, and stored in E <<Found>> begin -- Check violation of No_Wide_Characters restriction Check_Wide_Character_Restriction (E, N); -- When distribution features are available (Get_PCS_Name /= -- Name_No_DSA), a remote access-to-subprogram type is converted -- into a record type holding whatever information is needed to -- perform a remote call on an RCI subprogram. In that case we -- rewrite any occurrence of the RAS type into the equivalent record -- type here. 'Access attribute references and RAS dereferences are -- then implemented using specific TSSs. However when distribution is -- not available (case of Get_PCS_Name = Name_No_DSA), we bypass the -- generation of these TSSs, and we must keep the RAS type in its -- original access-to-subprogram form (since all calls through a -- value of such type will be local anyway in the absence of a PCS). if Comes_From_Source (N) and then Is_Remote_Access_To_Subprogram_Type (E) and then Expander_Active and then Get_PCS_Name /= Name_No_DSA then Rewrite (N, New_Occurrence_Of (Equivalent_Type (E), Sloc (N))); return; end if; -- Set the entity. Note that the reason we call Set_Entity for the -- overloadable case, as opposed to Set_Entity_With_Style_Check is -- that in the overloaded case, the initial call can set the wrong -- homonym. The call that sets the right homonym is in Sem_Res and -- that call does use Set_Entity_With_Style_Check, so we don't miss -- a style check. if Is_Overloadable (E) then Set_Entity (N, E); else Set_Entity_With_Style_Check (N, E); end if; if Is_Type (E) then Set_Etype (N, E); else Set_Etype (N, Get_Full_View (Etype (E))); end if; if Debug_Flag_E then Write_Str (" found "); Write_Entity_Info (E, " "); end if; -- If the Ekind of the entity is Void, it means that all homonyms -- are hidden from all visibility (RM 8.3(5,14-20)). However, this -- test is skipped if the current scope is a record and the name is -- a pragma argument expression (case of Atomic and Volatile pragmas -- and possibly other similar pragmas added later, which are allowed -- to reference components in the current record). if Ekind (E) = E_Void and then (not Is_Record_Type (Current_Scope) or else Nkind (Parent (N)) /= N_Pragma_Argument_Association) then Premature_Usage (N); -- If the entity is overloadable, collect all interpretations of the -- name for subsequent overload resolution. We optimize a bit here to -- do this only if we have an overloadable entity that is not on its -- own on the homonym chain. elsif Is_Overloadable (E) and then (Present (Homonym (E)) or else Current_Entity (N) /= E) then Collect_Interps (N); -- If no homonyms were visible, the entity is unambiguous if not Is_Overloaded (N) then if not Is_Actual_Parameter then Generate_Reference (E, N); end if; end if; -- Case of non-overloadable entity, set the entity providing that -- we do not have the case of a discriminant reference within a -- default expression. Such references are replaced with the -- corresponding discriminal, which is the formal corresponding to -- to the discriminant in the initialization procedure. else -- Entity is unambiguous, indicate that it is referenced here -- For a renaming of an object, always generate simple reference, -- we don't try to keep track of assignments in this case. if Is_Object (E) and then Present (Renamed_Object (E)) then Generate_Reference (E, N); -- If the renamed entity is a private protected component, -- reference the original component as well. This needs to be -- done because the private renamings are installed before any -- analysis has occurred. Reference to a private component will -- resolve to the renaming and the original component will be -- left unreferenced, hence the following. if Is_Prival (E) then Generate_Reference (Prival_Link (E), N); end if; -- One odd case is that we do not want to set the Referenced flag -- if the entity is a label, and the identifier is the label in -- the source, since this is not a reference from the point of -- view of the user. elsif Nkind (Parent (N)) = N_Label then declare R : constant Boolean := Referenced (E); begin -- Generate reference unless this is an actual parameter -- (see comment below) if Is_Actual_Parameter then Generate_Reference (E, N); Set_Referenced (E, R); end if; end; -- Normal case, not a label: generate reference -- ??? It is too early to generate a reference here even if the -- entity is unambiguous, because the tree is not sufficiently -- typed at this point for Generate_Reference to determine -- whether this reference modifies the denoted object (because -- implicit dereferences cannot be identified prior to full type -- resolution). -- The Is_Actual_Parameter routine takes care of one of these -- cases but there are others probably ??? -- If the entity is the LHS of an assignment, and is a variable -- (rather than a package prefix), we can mark it as a -- modification right away, to avoid duplicate references. else if not Is_Actual_Parameter then if Is_LHS (N) and then Ekind (E) /= E_Package and then Ekind (E) /= E_Generic_Package then Generate_Reference (E, N, 'm'); else Generate_Reference (E, N); end if; end if; Check_Nested_Access (E); end if; Set_Entity_Or_Discriminal (N, E); if Ada_Version >= Ada_2012 and then (Nkind (Parent (N)) in N_Subexpr or else Nkind (Parent (N)) = N_Object_Declaration) then Check_Implicit_Dereference (N, Etype (E)); end if; end if; end; end Find_Direct_Name; ------------------------ -- Find_Expanded_Name -- ------------------------ -- This routine searches the homonym chain of the entity until it finds -- an entity declared in the scope denoted by the prefix. If the entity -- is private, it may nevertheless be immediately visible, if we are in -- the scope of its declaration. procedure Find_Expanded_Name (N : Node_Id) is Selector : constant Node_Id := Selector_Name (N); Candidate : Entity_Id := Empty; P_Name : Entity_Id; O_Name : Entity_Id; Id : Entity_Id; begin P_Name := Entity (Prefix (N)); O_Name := P_Name; -- If the prefix is a renamed package, look for the entity in the -- original package. if Ekind (P_Name) = E_Package and then Present (Renamed_Object (P_Name)) then P_Name := Renamed_Object (P_Name); -- Rewrite node with entity field pointing to renamed object Rewrite (Prefix (N), New_Copy (Prefix (N))); Set_Entity (Prefix (N), P_Name); -- If the prefix is an object of a concurrent type, look for -- the entity in the associated task or protected type. elsif Is_Concurrent_Type (Etype (P_Name)) then P_Name := Etype (P_Name); end if; Id := Current_Entity (Selector); declare Is_New_Candidate : Boolean; begin while Present (Id) loop if Scope (Id) = P_Name then Candidate := Id; Is_New_Candidate := True; -- Ada 2005 (AI-217): Handle shadow entities associated with types -- declared in limited-withed nested packages. We don't need to -- handle E_Incomplete_Subtype entities because the entities in -- the limited view are always E_Incomplete_Type entities (see -- Build_Limited_Views). Regarding the expression used to evaluate -- the scope, it is important to note that the limited view also -- has shadow entities associated nested packages. For this reason -- the correct scope of the entity is the scope of the real entity -- The non-limited view may itself be incomplete, in which case -- get the full view if available. elsif From_With_Type (Id) and then Is_Type (Id) and then Ekind (Id) = E_Incomplete_Type and then Present (Non_Limited_View (Id)) and then Scope (Non_Limited_View (Id)) = P_Name then Candidate := Get_Full_View (Non_Limited_View (Id)); Is_New_Candidate := True; else Is_New_Candidate := False; end if; if Is_New_Candidate then if Is_Child_Unit (Id) 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; end; if No (Id) and then (Ekind (P_Name) = E_Procedure or else Ekind (P_Name) = E_Function) and then Is_Generic_Instance (P_Name) then -- Expanded name denotes entity in (instance of) generic subprogram. -- The entity may be in the subprogram instance, or may denote one of -- the formals, which is declared in the enclosing wrapper package. P_Name := Scope (P_Name); Id := Current_Entity (Selector); while Present (Id) loop exit when Scope (Id) = P_Name; Id := Homonym (Id); end loop; end if; if No (Id) or else Chars (Id) /= Chars (Selector) then Set_Etype (N, Any_Type); -- If we are looking for an entity defined in System, try to find it -- in the child package that may have been provided as an extension -- to System. The Extend_System pragma will have supplied the name of -- the extension, which may have to be loaded. if Chars (P_Name) = Name_System and then Scope (P_Name) = Standard_Standard and then Present (System_Extend_Unit) and then Present_System_Aux (N) then Set_Entity (Prefix (N), System_Aux_Id); Find_Expanded_Name (N); return; elsif Nkind (Selector) = N_Operator_Symbol and then Has_Implicit_Operator (N) then -- There is an implicit instance of the predefined operator in -- the given scope. The operator entity is defined in Standard. -- Has_Implicit_Operator makes the node into an Expanded_Name. return; elsif Nkind (Selector) = N_Character_Literal and then Has_Implicit_Character_Literal (N) then -- If there is no literal defined in the scope denoted by the -- prefix, the literal may belong to (a type derived from) -- Standard_Character, for which we have no explicit literals. return; else -- If the prefix is a single concurrent object, use its name in -- the error message, rather than that of the anonymous type. if Is_Concurrent_Type (P_Name) and then Is_Internal_Name (Chars (P_Name)) then Error_Msg_Node_2 := Entity (Prefix (N)); else Error_Msg_Node_2 := P_Name; end if; if P_Name = System_Aux_Id then P_Name := Scope (P_Name); Set_Entity (Prefix (N), P_Name); end if; if Present (Candidate) then -- If we know that the unit is a child unit we can give a more -- accurate error message. if Is_Child_Unit (Candidate) then -- If the candidate is a private child unit and we are in -- the visible part of a public unit, specialize the error -- message. There might be a private with_clause for it, -- but it is not currently active. if Is_Private_Descendant (Candidate) and then Ekind (Current_Scope) = E_Package and then not In_Private_Part (Current_Scope) and then not Is_Private_Descendant (Current_Scope) then Error_Msg_N ("private child unit& is not visible here", Selector); -- Normal case where we have a missing with for a child unit else Error_Msg_Qual_Level := 99; Error_Msg_NE -- CODEFIX ("missing `WITH &;`", Selector, Candidate); Error_Msg_Qual_Level := 0; end if; -- Here we don't know that this is a child unit else Error_Msg_NE ("& is not a visible entity of&", N, Selector); end if; else -- Within the instantiation of a child unit, the prefix may -- denote the parent instance, but the selector has the name -- of the original child. Find whether we are within the -- corresponding instance, and get the proper entity, which -- can only be an enclosing scope. if O_Name /= P_Name and then In_Open_Scopes (P_Name) and then Is_Generic_Instance (P_Name) then declare S : Entity_Id := Current_Scope; P : Entity_Id; begin for J in reverse 0 .. Scope_Stack.Last loop S := Scope_Stack.Table (J).Entity; exit when S = Standard_Standard; if Ekind_In (S, E_Function, E_Package, E_Procedure) then P := Generic_Parent (Specification (Unit_Declaration_Node (S))); if Present (P) and then Chars (Scope (P)) = Chars (O_Name) and then Chars (P) = Chars (Selector) then Id := S; goto Found; end if; end if; end loop; end; end if; -- If this is a selection from Ada, System or Interfaces, then -- we assume a missing with for the corresponding package. if Is_Known_Unit (N) then if not Error_Posted (N) then Error_Msg_Node_2 := Selector; Error_Msg_N -- CODEFIX ("missing `WITH &.&;`", Prefix (N)); end if; -- If this is a selection from a dummy package, then suppress -- the error message, of course the entity is missing if the -- package is missing! elsif Sloc (Error_Msg_Node_2) = No_Location then null; -- Here we have the case of an undefined component else -- The prefix may hide a homonym in the context that -- declares the desired entity. This error can use a -- specialized message. if In_Open_Scopes (P_Name) and then Present (Homonym (P_Name)) and then Is_Compilation_Unit (Homonym (P_Name)) and then (Is_Immediately_Visible (Homonym (P_Name)) or else Is_Visible_Child_Unit (Homonym (P_Name))) then declare H : constant Entity_Id := Homonym (P_Name); begin Id := First_Entity (H); while Present (Id) loop if Chars (Id) = Chars (Selector) then Error_Msg_Qual_Level := 99; Error_Msg_Name_1 := Chars (Selector); Error_Msg_NE ("% not declared in&", N, P_Name); Error_Msg_NE ("\use fully qualified name starting with" & " Standard to make& visible", N, H); Error_Msg_Qual_Level := 0; goto Done; end if; Next_Entity (Id); end loop; -- If not found, standard error message Error_Msg_NE ("& not declared in&", N, Selector); <<Done>> null; end; else Error_Msg_NE ("& not declared in&", N, Selector); end if; -- Check for misspelling of some entity in prefix Id := First_Entity (P_Name); while Present (Id) loop if Is_Bad_Spelling_Of (Chars (Id), Chars (Selector)) and then not Is_Internal_Name (Chars (Id)) then Error_Msg_NE -- CODEFIX ("possible misspelling of&", Selector, Id); exit; end if; Next_Entity (Id); end loop; -- Specialize the message if this may be an instantiation -- of a child unit that was not mentioned in the context. if Nkind (Parent (N)) = N_Package_Instantiation and then Is_Generic_Instance (Entity (Prefix (N))) and then Is_Compilation_Unit (Generic_Parent (Parent (Entity (Prefix (N))))) then Error_Msg_Node_2 := Selector; Error_Msg_N -- CODEFIX ("\missing `WITH &.&;`", Prefix (N)); end if; end if; end if; Id := Any_Id; end if; end if; <<Found>> if Comes_From_Source (N) and then Is_Remote_Access_To_Subprogram_Type (Id) and then Present (Equivalent_Type (Id)) then -- If we are not actually generating distribution code (i.e. the -- current PCS is the dummy non-distributed version), then the -- Equivalent_Type will be missing, and Id should be treated as -- a regular access-to-subprogram type. Id := Equivalent_Type (Id); Set_Chars (Selector, Chars (Id)); end if; -- Ada 2005 (AI-50217): Check usage of entities in limited withed units if Ekind (P_Name) = E_Package and then From_With_Type (P_Name) then if From_With_Type (Id) or else Is_Type (Id) or else Ekind (Id) = E_Package then null; else Error_Msg_N ("limited withed package can only be used to access " & "incomplete types", N); end if; end if; if Is_Task_Type (P_Name) and then ((Ekind (Id) = E_Entry and then Nkind (Parent (N)) /= N_Attribute_Reference) or else (Ekind (Id) = E_Entry_Family and then Nkind (Parent (Parent (N))) /= N_Attribute_Reference)) then -- 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_Or_Discriminal (N, Id); if Is_LHS (N) then Generate_Reference (Id, N, 'm'); else Generate_Reference (Id, N); end if; end if; if Is_Type (Id) then Set_Etype (N, Id); else Set_Etype (N, Get_Full_View (Etype (Id))); end if; -- Check for violation of No_Wide_Characters Check_Wide_Character_Restriction (Id, N); -- If the Ekind of the entity is Void, it means that all homonyms are -- hidden from all visibility (RM 8.3(5,14-20)). if Ekind (Id) = E_Void then Premature_Usage (N); elsif Is_Overloadable (Id) and then Present (Homonym (Id)) then declare H : Entity_Id := Homonym (Id); begin while Present (H) loop if Scope (H) = Scope (Id) and then (not Is_Hidden (H) or else Is_Immediately_Visible (H)) then Collect_Interps (N); exit; end if; H := Homonym (H); end loop; -- If an extension of System is present, collect possible explicit -- overloadings declared in the extension. if Chars (P_Name) = Name_System and then Scope (P_Name) = Standard_Standard and then Present (System_Extend_Unit) and then Present_System_Aux (N) then H := Current_Entity (Id); while Present (H) loop if Scope (H) = System_Aux_Id then Add_One_Interp (N, H, Etype (H)); end if; H := Homonym (H); end loop; end if; end; end if; if Nkind (Selector_Name (N)) = N_Operator_Symbol and then Scope (Id) /= Standard_Standard then -- In addition to user-defined operators in the given scope, there -- may be an implicit instance of the predefined operator. The -- operator (defined in Standard) is found in Has_Implicit_Operator, -- and added to the interpretations. Procedure Add_One_Interp will -- determine which hides which. if Has_Implicit_Operator (N) then null; end if; end if; end Find_Expanded_Name; ------------------------- -- Find_Renamed_Entity -- ------------------------- function Find_Renamed_Entity (N : Node_Id; Nam : Node_Id; New_S : Entity_Id; Is_Actual : Boolean := False) return Entity_Id is Ind : Interp_Index; I1 : Interp_Index := 0; -- Suppress junk warnings It : Interp; It1 : Interp; Old_S : Entity_Id; Inst : Entity_Id; function Enclosing_Instance return Entity_Id; -- If the renaming determines the entity for the default of a formal -- subprogram nested within another instance, choose the innermost -- candidate. This is because if the formal has a box, and we are within -- an enclosing instance where some candidate interpretations are local -- to this enclosing instance, we know that the default was properly -- resolved when analyzing the generic, so we prefer the local -- candidates to those that are external. This is not always the case -- but is a reasonable heuristic on the use of nested generics. The -- proper solution requires a full renaming model. function Is_Visible_Operation (Op : Entity_Id) return Boolean; -- If the renamed entity is an implicit operator, check whether it is -- visible because its operand type is properly visible. This check -- applies to explicit renamed entities that appear in the source in a -- renaming declaration or a formal subprogram instance, but not to -- default generic actuals with a name. function Report_Overload return Entity_Id; -- List possible interpretations, and specialize message in the -- case of a generic actual. function Within (Inner, Outer : Entity_Id) return Boolean; -- Determine whether a candidate subprogram is defined within the -- enclosing instance. If yes, it has precedence over outer candidates. ------------------------ -- Enclosing_Instance -- ------------------------ function Enclosing_Instance return Entity_Id is S : Entity_Id; begin if not Is_Generic_Instance (Current_Scope) and then not Is_Actual then return Empty; end if; S := Scope (Current_Scope); while S /= Standard_Standard loop if Is_Generic_Instance (S) then return S; end if; S := Scope (S); end loop; return Empty; end Enclosing_Instance; -------------------------- -- Is_Visible_Operation -- -------------------------- function Is_Visible_Operation (Op : Entity_Id) return Boolean is Scop : Entity_Id; Typ : Entity_Id; Btyp : Entity_Id; begin if Ekind (Op) /= E_Operator or else Scope (Op) /= Standard_Standard or else (In_Instance and then (not Is_Actual or else Present (Enclosing_Instance))) then return True; else -- For a fixed point type operator, check the resulting type, -- because it may be a mixed mode integer * fixed operation. if Present (Next_Formal (First_Formal (New_S))) and then Is_Fixed_Point_Type (Etype (New_S)) then Typ := Etype (New_S); else Typ := Etype (First_Formal (New_S)); end if; Btyp := Base_Type (Typ); if Nkind (Nam) /= N_Expanded_Name then return (In_Open_Scopes (Scope (Btyp)) or else Is_Potentially_Use_Visible (Btyp) or else In_Use (Btyp) or else In_Use (Scope (Btyp))); else Scop := Entity (Prefix (Nam)); if Ekind (Scop) = E_Package and then Present (Renamed_Object (Scop)) then Scop := Renamed_Object (Scop); end if; -- Operator is visible if prefix of expanded name denotes -- scope of type, or else type is defined in System_Aux -- and the prefix denotes System. return Scope (Btyp) = Scop or else (Scope (Btyp) = System_Aux_Id and then Scope (Scope (Btyp)) = Scop); end if; end if; end Is_Visible_Operation; ------------ -- Within -- ------------ function Within (Inner, Outer : Entity_Id) return Boolean is Sc : Entity_Id; begin Sc := Scope (Inner); while Sc /= Standard_Standard loop if Sc = Outer then return True; else Sc := Scope (Sc); end if; end loop; return False; end Within; --------------------- -- Report_Overload -- --------------------- function Report_Overload return Entity_Id is begin if Is_Actual then Error_Msg_NE -- CODEFIX ("ambiguous actual subprogram&, " & "possible interpretations:", N, Nam); else Error_Msg_N -- CODEFIX ("ambiguous subprogram, " & "possible interpretations:", N); end if; List_Interps (Nam, N); return Old_S; end Report_Overload; -- Start of processing for Find_Renamed_Entity begin Old_S := Any_Id; Candidate_Renaming := Empty; if not Is_Overloaded (Nam) then if Entity_Matches_Spec (Entity (Nam), New_S) then Candidate_Renaming := New_S; if Is_Visible_Operation (Entity (Nam)) then Old_S := Entity (Nam); end if; elsif Present (First_Formal (Entity (Nam))) and then Present (First_Formal (New_S)) and then (Base_Type (Etype (First_Formal (Entity (Nam)))) = Base_Type (Etype (First_Formal (New_S)))) then Candidate_Renaming := Entity (Nam); end if; else Get_First_Interp (Nam, Ind, It); while Present (It.Nam) loop if Entity_Matches_Spec (It.Nam, New_S) and then Is_Visible_Operation (It.Nam) then if Old_S /= Any_Id then -- Note: The call to Disambiguate only happens if a -- previous interpretation was found, in which case I1 -- has received a value. It1 := Disambiguate (Nam, I1, Ind, Etype (Old_S)); if It1 = No_Interp then Inst := Enclosing_Instance; if Present (Inst) then if Within (It.Nam, Inst) then if Within (Old_S, Inst) then -- Choose the innermost subprogram, which would -- have hidden the outer one in the generic. if Scope_Depth (It.Nam) < Scope_Depth (Old_S) then return Old_S; else return It.Nam; end if; end if; elsif Within (Old_S, Inst) then return (Old_S); else return Report_Overload; end if; -- If not within an instance, ambiguity is real else return Report_Overload; end if; else Old_S := It1.Nam; exit; end if; else I1 := Ind; Old_S := It.Nam; end if; elsif Present (First_Formal (It.Nam)) and then Present (First_Formal (New_S)) and then (Base_Type (Etype (First_Formal (It.Nam))) = Base_Type (Etype (First_Formal (New_S)))) then Candidate_Renaming := It.Nam; end if; Get_Next_Interp (Ind, It); end loop; Set_Entity (Nam, Old_S); if Old_S /= Any_Id then Set_Is_Overloaded (Nam, False); end if; end if; return Old_S; end Find_Renamed_Entity; ----------------------------- -- Find_Selected_Component -- ----------------------------- procedure Find_Selected_Component (N : Node_Id) is P : constant Node_Id := Prefix (N); P_Name : Entity_Id; -- Entity denoted by prefix P_Type : Entity_Id; -- and its type Nam : Node_Id; begin Analyze (P); if Nkind (P) = N_Error then return; end if; -- Selector name cannot be a character literal or an operator symbol in -- SPARK, except for the operator symbol in a renaming. if Restriction_Check_Required (SPARK) then if Nkind (Selector_Name (N)) = N_Character_Literal then Check_SPARK_Restriction ("character literal cannot be prefixed", N); elsif Nkind (Selector_Name (N)) = N_Operator_Symbol and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration then Check_SPARK_Restriction ("operator symbol cannot be prefixed", N); end if; end if; -- If the selector already has an entity, the node has been constructed -- in the course of expansion, and is known to be valid. Do not verify -- that it is defined for the type (it may be a private component used -- in the expansion of record equality). if Present (Entity (Selector_Name (N))) then if No (Etype (N)) or else Etype (N) = Any_Type then declare Sel_Name : constant Node_Id := Selector_Name (N); Selector : constant Entity_Id := Entity (Sel_Name); C_Etype : Node_Id; begin Set_Etype (Sel_Name, Etype (Selector)); if not Is_Entity_Name (P) then Resolve (P); end if; -- Build an actual subtype except for the first parameter -- of an init proc, where this actual subtype is by -- definition incorrect, since the object is uninitialized -- (and does not even have defined discriminants etc.) if Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Function then Nam := New_Copy (P); if Is_Overloaded (P) then Save_Interps (P, Nam); end if; Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam)); Analyze_Call (P); Analyze_Selected_Component (N); return; elsif Ekind (Selector) = E_Component and then (not Is_Entity_Name (P) or else Chars (Entity (P)) /= Name_uInit) then -- Do not build the subtype when referencing components of -- dispatch table wrappers. Required to avoid generating -- elaboration code with HI runtimes. JVM and .NET use a -- modified version of Ada.Tags which does not contain RE_ -- Dispatch_Table_Wrapper and RE_No_Dispatch_Table_Wrapper. -- Avoid raising RE_Not_Available exception in those cases. if VM_Target = No_VM and then RTU_Loaded (Ada_Tags) and then ((RTE_Available (RE_Dispatch_Table_Wrapper) and then Scope (Selector) = RTE (RE_Dispatch_Table_Wrapper)) or else (RTE_Available (RE_No_Dispatch_Table_Wrapper) and then Scope (Selector) = RTE (RE_No_Dispatch_Table_Wrapper))) then C_Etype := Empty; else C_Etype := Build_Actual_Subtype_Of_Component (Etype (Selector), N); end if; else C_Etype := Empty; end if; if No (C_Etype) then C_Etype := Etype (Selector); else Insert_Action (N, C_Etype); C_Etype := Defining_Identifier (C_Etype); end if; Set_Etype (N, C_Etype); end; -- If this is the name of an entry or protected operation, and -- the prefix is an access type, insert an explicit dereference, -- so that entry calls are treated uniformly. if Is_Access_Type (Etype (P)) and then Is_Concurrent_Type (Designated_Type (Etype (P))) then declare New_P : constant Node_Id := Make_Explicit_Dereference (Sloc (P), Prefix => Relocate_Node (P)); begin Rewrite (P, New_P); Set_Etype (P, Designated_Type (Etype (Prefix (P)))); end; end if; -- If the selected component appears within a default expression -- and it has an actual subtype, the pre-analysis has not yet -- completed its analysis, because Insert_Actions is disabled in -- that context. Within the init proc of the enclosing type we -- must complete this analysis, if an actual subtype was created. elsif Inside_Init_Proc then declare Typ : constant Entity_Id := Etype (N); Decl : constant Node_Id := Declaration_Node (Typ); begin if Nkind (Decl) = N_Subtype_Declaration and then not Analyzed (Decl) and then Is_List_Member (Decl) and then No (Parent (Decl)) then Remove (Decl); Insert_Action (N, Decl); end if; end; end if; return; elsif Is_Entity_Name (P) then P_Name := Entity (P); -- The prefix may denote an enclosing type which is the completion -- of an incomplete type declaration. if Is_Type (P_Name) then Set_Entity (P, Get_Full_View (P_Name)); Set_Etype (P, Entity (P)); P_Name := Entity (P); end if; P_Type := Base_Type (Etype (P)); if Debug_Flag_E then Write_Str ("Found prefix type to be "); Write_Entity_Info (P_Type, " "); Write_Eol; end if; -- First check for components of a record object (not the -- result of a call, which is handled below). if Is_Appropriate_For_Record (P_Type) and then not Is_Overloadable (P_Name) and then not Is_Type (P_Name) then -- Selected component of record. Type checking will validate -- name of selector. -- ??? could we rewrite an implicit dereference into an explicit -- one here? Analyze_Selected_Component (N); -- Reference to type name in predicate/invariant expression elsif Is_Appropriate_For_Entry_Prefix (P_Type) and then not In_Open_Scopes (P_Name) and then (not Is_Concurrent_Type (Etype (P_Name)) or else not In_Open_Scopes (Etype (P_Name))) then -- Call to protected operation or entry. Type checking is -- needed on the prefix. Analyze_Selected_Component (N); elsif (In_Open_Scopes (P_Name) and then Ekind (P_Name) /= E_Void and then not Is_Overloadable (P_Name)) or else (Is_Concurrent_Type (Etype (P_Name)) and then In_Open_Scopes (Etype (P_Name))) then -- Prefix denotes an enclosing loop, block, or task, i.e. an -- enclosing construct that is not a subprogram or accept. Find_Expanded_Name (N); elsif Ekind (P_Name) = E_Package then Find_Expanded_Name (N); elsif Is_Overloadable (P_Name) then -- The subprogram may be a renaming (of an enclosing scope) as -- in the case of the name of the generic within an instantiation. if Ekind_In (P_Name, E_Procedure, E_Function) and then Present (Alias (P_Name)) and then Is_Generic_Instance (Alias (P_Name)) then P_Name := Alias (P_Name); end if; if Is_Overloaded (P) then -- The prefix must resolve to a unique enclosing construct declare Found : Boolean := False; Ind : Interp_Index; It : Interp; begin Get_First_Interp (P, Ind, It); while Present (It.Nam) loop if In_Open_Scopes (It.Nam) then if Found then Error_Msg_N ( "prefix must be unique enclosing scope", N); Set_Entity (N, Any_Id); Set_Etype (N, Any_Type); return; else Found := True; P_Name := It.Nam; end if; end if; Get_Next_Interp (Ind, It); end loop; end; end if; if In_Open_Scopes (P_Name) then Set_Entity (P, P_Name); Set_Is_Overloaded (P, False); Find_Expanded_Name (N); else -- If no interpretation as an expanded name is possible, it -- must be a selected component of a record returned by a -- function call. Reformat prefix as a function call, the rest -- is done by type resolution. If the prefix is procedure or -- entry, as is P.X; this is an error. if Ekind (P_Name) /= E_Function and then (not Is_Overloaded (P) or else Nkind (Parent (N)) = N_Procedure_Call_Statement) then -- Prefix may mention a package that is hidden by a local -- declaration: let the user know. Scan the full homonym -- chain, the candidate package may be anywhere on it. if Present (Homonym (Current_Entity (P_Name))) then P_Name := Current_Entity (P_Name); while Present (P_Name) loop exit when Ekind (P_Name) = E_Package; P_Name := Homonym (P_Name); end loop; if Present (P_Name) then Error_Msg_Sloc := Sloc (Entity (Prefix (N))); Error_Msg_NE ("package& is hidden by declaration#", N, P_Name); Set_Entity (Prefix (N), P_Name); Find_Expanded_Name (N); return; else P_Name := Entity (Prefix (N)); end if; end if; Error_Msg_NE ("invalid prefix in selected component&", N, P_Name); Change_Selected_Component_To_Expanded_Name (N); Set_Entity (N, Any_Id); Set_Etype (N, Any_Type); else Nam := New_Copy (P); Save_Interps (P, Nam); Rewrite (P, Make_Function_Call (Sloc (P), Name => Nam)); Analyze_Call (P); Analyze_Selected_Component (N); end if; end if; -- Remaining cases generate various error messages else -- Format node as expanded name, to avoid cascaded errors Change_Selected_Component_To_Expanded_Name (N); Set_Entity (N, Any_Id); Set_Etype (N, Any_Type); -- Issue error message, but avoid this if error issued already. -- Use identifier of prefix if one is available. if P_Name = Any_Id then null; elsif Ekind (P_Name) = E_Void then Premature_Usage (P); elsif Nkind (P) /= N_Attribute_Reference then Error_Msg_N ( "invalid prefix in selected component&", P); if Is_Access_Type (P_Type) and then Ekind (Designated_Type (P_Type)) = E_Incomplete_Type then Error_Msg_N ("\dereference must not be of an incomplete type " & "(RM 3.10.1)", P); end if; else Error_Msg_N ( "invalid prefix in selected component", P); end if; end if; -- Selector name is restricted in SPARK if Nkind (N) = N_Expanded_Name and then Restriction_Check_Required (SPARK) then if Is_Subprogram (P_Name) then Check_SPARK_Restriction ("prefix of expanded name cannot be a subprogram", P); elsif Ekind (P_Name) = E_Loop then Check_SPARK_Restriction ("prefix of expanded name cannot be a loop statement", P); end if; end if; else -- If prefix is not the name of an entity, it must be an expression, -- whose type is appropriate for a record. This is determined by -- type resolution. Analyze_Selected_Component (N); end if; end Find_Selected_Component; --------------- -- Find_Type -- --------------- procedure Find_Type (N : Node_Id) is C : Entity_Id; Typ : Entity_Id; T : Entity_Id; T_Name : Entity_Id; begin if N = Error then return; elsif Nkind (N) = N_Attribute_Reference then -- Class attribute. This is not valid in Ada 83 mode, but we do not -- need to enforce that at this point, since the declaration of the -- tagged type in the prefix would have been flagged already. if Attribute_Name (N) = Name_Class then Check_Restriction (No_Dispatch, N); Find_Type (Prefix (N)); -- Propagate error from bad prefix if Etype (Prefix (N)) = Any_Type then Set_Entity (N, Any_Type); Set_Etype (N, Any_Type); return; end if; T := Base_Type (Entity (Prefix (N))); -- Case where type is not known to be tagged. Its appearance in -- the prefix of the 'Class attribute indicates that the full view -- will be tagged. if not Is_Tagged_Type (T) then if Ekind (T) = E_Incomplete_Type then -- It is legal to denote the class type of an incomplete -- type. The full type will have to be tagged, of course. -- In Ada 2005 this usage is declared obsolescent, so we -- warn accordingly. This usage is only legal if the type -- is completed in the current scope, and not for a limited -- view of a type. if Ada_Version >= Ada_2005 then -- Test whether the Available_View of a limited type view -- is tagged, since the limited view may not be marked as -- tagged if the type itself has an untagged incomplete -- type view in its package. if From_With_Type (T) and then not Is_Tagged_Type (Available_View (T)) then Error_Msg_N ("prefix of Class attribute must be tagged", N); Set_Etype (N, Any_Type); Set_Entity (N, Any_Type); return; -- ??? This test is temporarily disabled (always False) -- because it causes an unwanted warning on GNAT sources -- (built with -gnatg, which includes Warn_On_Obsolescent_ -- Feature). Once this issue is cleared in the sources, it -- can be enabled. elsif Warn_On_Obsolescent_Feature and then False then Error_Msg_N ("applying 'Class to an untagged incomplete type" & " is an obsolescent feature (RM J.11)", N); end if; end if; Set_Is_Tagged_Type (T); Set_Direct_Primitive_Operations (T, New_Elmt_List); Make_Class_Wide_Type (T); Set_Entity (N, Class_Wide_Type (T)); Set_Etype (N, Class_Wide_Type (T)); elsif Ekind (T) = E_Private_Type and then not Is_Generic_Type (T) and then In_Private_Part (Scope (T)) then -- The Class attribute can be applied to an untagged private -- type fulfilled by a tagged type prior to the full type -- declaration (but only within the parent package's private -- part). Create the class-wide type now and check that the -- full type is tagged later during its analysis. Note that -- we do not mark the private type as tagged, unlike the -- case of incomplete types, because the type must still -- appear untagged to outside units. if No (Class_Wide_Type (T)) then Make_Class_Wide_Type (T); end if; Set_Entity (N, Class_Wide_Type (T)); Set_Etype (N, Class_Wide_Type (T)); else -- Should we introduce a type Any_Tagged and use Wrong_Type -- here, it would be a bit more consistent??? Error_Msg_NE ("tagged type required, found}", Prefix (N), First_Subtype (T)); Set_Entity (N, Any_Type); return; end if; -- Case of tagged type else if Is_Concurrent_Type (T) then if No (Corresponding_Record_Type (Entity (Prefix (N)))) then -- Previous error. Use current type, which at least -- provides some operations. C := Entity (Prefix (N)); else C := Class_Wide_Type (Corresponding_Record_Type (Entity (Prefix (N)))); end if; else C := Class_Wide_Type (Entity (Prefix (N))); end if; Set_Entity_With_Style_Check (N, C); Generate_Reference (C, N); Set_Etype (N, C); end if; -- Base attribute, not allowed in Ada 83 elsif Attribute_Name (N) = Name_Base then Error_Msg_Name_1 := Name_Base; Check_SPARK_Restriction ("attribute% is only allowed as prefix of another attribute", N); if Ada_Version = Ada_83 and then Comes_From_Source (N) then Error_Msg_N ("(Ada 83) Base attribute not allowed in subtype mark", N); else Find_Type (Prefix (N)); Typ := Entity (Prefix (N)); if Ada_Version >= Ada_95 and then not Is_Scalar_Type (Typ) and then not Is_Generic_Type (Typ) then Error_Msg_N ("prefix of Base attribute must be scalar type", Prefix (N)); elsif Warn_On_Redundant_Constructs and then Base_Type (Typ) = Typ then Error_Msg_NE -- CODEFIX ("?redundant attribute, & is its own base type", N, Typ); end if; T := Base_Type (Typ); -- Rewrite attribute reference with type itself (see similar -- processing in Analyze_Attribute, case Base). Preserve prefix -- if present, for other legality checks. if Nkind (Prefix (N)) = N_Expanded_Name then Rewrite (N, Make_Expanded_Name (Sloc (N), Chars => Chars (T), Prefix => New_Copy (Prefix (Prefix (N))), Selector_Name => New_Reference_To (T, Sloc (N)))); else Rewrite (N, New_Reference_To (T, Sloc (N))); end if; Set_Entity (N, T); Set_Etype (N, T); end if; elsif Attribute_Name (N) = Name_Stub_Type then -- This is handled in Analyze_Attribute Analyze (N); -- All other attributes are invalid in a subtype mark else Error_Msg_N ("invalid attribute in subtype mark", N); end if; else Analyze (N); if Is_Entity_Name (N) then T_Name := Entity (N); else Error_Msg_N ("subtype mark required in this context", N); Set_Etype (N, Any_Type); return; end if; if T_Name = Any_Id or else Etype (N) = Any_Type then -- Undefined id. Make it into a valid type Set_Entity (N, Any_Type); elsif not Is_Type (T_Name) and then T_Name /= Standard_Void_Type then Error_Msg_Sloc := Sloc (T_Name); Error_Msg_N ("subtype mark required in this context", N); Error_Msg_NE ("\\found & declared#", N, T_Name); Set_Entity (N, Any_Type); else -- If the type is an incomplete type created to handle -- anonymous access components of a record type, then the -- incomplete type is the visible entity and subsequent -- references will point to it. Mark the original full -- type as referenced, to prevent spurious warnings. if Is_Incomplete_Type (T_Name) and then Present (Full_View (T_Name)) and then not Comes_From_Source (T_Name) then Set_Referenced (Full_View (T_Name)); end if; T_Name := Get_Full_View (T_Name); -- Ada 2005 (AI-251, AI-50217): Handle interfaces visible through -- limited-with clauses if From_With_Type (T_Name) and then Ekind (T_Name) in Incomplete_Kind and then Present (Non_Limited_View (T_Name)) and then Is_Interface (Non_Limited_View (T_Name)) then T_Name := Non_Limited_View (T_Name); end if; if In_Open_Scopes (T_Name) then if Ekind (Base_Type (T_Name)) = E_Task_Type then -- In Ada 2005, a task name can be used in an access -- definition within its own body. It cannot be used -- in the discriminant part of the task declaration, -- nor anywhere else in the declaration because entries -- cannot have access parameters. if Ada_Version >= Ada_2005 and then Nkind (Parent (N)) = N_Access_Definition then Set_Entity (N, T_Name); Set_Etype (N, T_Name); if Has_Completion (T_Name) then return; else Error_Msg_N ("task type cannot be used as type mark " & "within its own declaration", N); end if; else Error_Msg_N ("task type cannot be used as type mark " & "within its own spec or body", N); end if; elsif Ekind (Base_Type (T_Name)) = E_Protected_Type then -- In Ada 2005, a protected name can be used in an access -- definition within its own body. if Ada_Version >= Ada_2005 and then Nkind (Parent (N)) = N_Access_Definition then Set_Entity (N, T_Name); Set_Etype (N, T_Name); return; else Error_Msg_N ("protected type cannot be used as type mark " & "within its own spec or body", N); end if; else Error_Msg_N ("type declaration cannot refer to itself", N); end if; Set_Etype (N, Any_Type); Set_Entity (N, Any_Type); Set_Error_Posted (T_Name); return; end if; Set_Entity (N, T_Name); Set_Etype (N, T_Name); end if; end if; if Present (Etype (N)) and then Comes_From_Source (N) then if Is_Fixed_Point_Type (Etype (N)) then Check_Restriction (No_Fixed_Point, N); elsif Is_Floating_Point_Type (Etype (N)) then Check_Restriction (No_Floating_Point, N); end if; end if; end Find_Type; ------------------------------------ -- Has_Implicit_Character_Literal -- ------------------------------------ function Has_Implicit_Character_Literal (N : Node_Id) return Boolean is Id : Entity_Id; Found : Boolean := False; P : constant Entity_Id := Entity (Prefix (N)); Priv_Id : Entity_Id := Empty; begin if Ekind (P) = E_Package and then not In_Open_Scopes (P) then Priv_Id := First_Private_Entity (P); end if; if P = Standard_Standard then Change_Selected_Component_To_Expanded_Name (N); Rewrite (N, Selector_Name (N)); Analyze (N); Set_Etype (Original_Node (N), Standard_Character); return True; end if; Id := First_Entity (P); while Present (Id) and then Id /= Priv_Id loop if Is_Standard_Character_Type (Id) and then Is_Base_Type (Id) then -- We replace the node with the literal itself, resolve as a -- character, and set the type correctly. if not Found then Change_Selected_Component_To_Expanded_Name (N); Rewrite (N, Selector_Name (N)); Analyze (N); Set_Etype (N, Id); Set_Etype (Original_Node (N), Id); Found := True; else -- More than one type derived from Character in given scope. -- Collect all possible interpretations. Add_One_Interp (N, Id, Id); end if; end if; Next_Entity (Id); end loop; return Found; end Has_Implicit_Character_Literal; ---------------------- -- Has_Private_With -- ---------------------- function Has_Private_With (E : Entity_Id) return Boolean is Comp_Unit : constant Node_Id := Cunit (Current_Sem_Unit); Item : Node_Id; begin Item := First (Context_Items (Comp_Unit)); while Present (Item) loop if Nkind (Item) = N_With_Clause and then Private_Present (Item) and then Entity (Name (Item)) = E then return True; end if; Next (Item); end loop; return False; end Has_Private_With; --------------------------- -- Has_Implicit_Operator -- --------------------------- function Has_Implicit_Operator (N : Node_Id) return Boolean is Op_Id : constant Name_Id := Chars (Selector_Name (N)); P : constant Entity_Id := Entity (Prefix (N)); Id : Entity_Id; Priv_Id : Entity_Id := Empty; procedure Add_Implicit_Operator (T : Entity_Id; Op_Type : Entity_Id := Empty); -- Add implicit interpretation to node N, using the type for which a -- predefined operator exists. If the operator yields a boolean type, -- the Operand_Type is implicitly referenced by the operator, and a -- reference to it must be generated. --------------------------- -- Add_Implicit_Operator -- --------------------------- procedure Add_Implicit_Operator (T : Entity_Id; Op_Type : Entity_Id := Empty) is Predef_Op : Entity_Id; begin Predef_Op := Current_Entity (Selector_Name (N)); while Present (Predef_Op) and then Scope (Predef_Op) /= Standard_Standard loop Predef_Op := Homonym (Predef_Op); end loop; if Nkind (N) = N_Selected_Component then Change_Selected_Component_To_Expanded_Name (N); end if; -- If the context is an unanalyzed function call, determine whether -- a binary or unary interpretation is required. if Nkind (Parent (N)) = N_Indexed_Component then declare Is_Binary_Call : constant Boolean := Present (Next (First (Expressions (Parent (N))))); Is_Binary_Op : constant Boolean := First_Entity (Predef_Op) /= Last_Entity (Predef_Op); Predef_Op2 : constant Entity_Id := Homonym (Predef_Op); begin if Is_Binary_Call then if Is_Binary_Op then Add_One_Interp (N, Predef_Op, T); else Add_One_Interp (N, Predef_Op2, T); end if; else if not Is_Binary_Op then Add_One_Interp (N, Predef_Op, T); else Add_One_Interp (N, Predef_Op2, T); end if; end if; end; else Add_One_Interp (N, Predef_Op, T); -- For operators with unary and binary interpretations, if -- context is not a call, add both if Present (Homonym (Predef_Op)) then Add_One_Interp (N, Homonym (Predef_Op), T); end if; end if; -- The node is a reference to a predefined operator, and -- an implicit reference to the type of its operands. if Present (Op_Type) then Generate_Operator_Reference (N, Op_Type); else Generate_Operator_Reference (N, T); end if; end Add_Implicit_Operator; -- Start of processing for Has_Implicit_Operator begin if Ekind (P) = E_Package and then not In_Open_Scopes (P) then Priv_Id := First_Private_Entity (P); end if; Id := First_Entity (P); case Op_Id is -- Boolean operators: an implicit declaration exists if the scope -- contains a declaration for a derived Boolean type, or for an -- array of Boolean type. when Name_Op_And | Name_Op_Not | Name_Op_Or | Name_Op_Xor => while Id /= Priv_Id loop if Valid_Boolean_Arg (Id) and then Is_Base_Type (Id) then Add_Implicit_Operator (Id); return True; end if; Next_Entity (Id); end loop; -- Equality: look for any non-limited type (result is Boolean) when Name_Op_Eq | Name_Op_Ne => while Id /= Priv_Id loop if Is_Type (Id) and then not Is_Limited_Type (Id) and then Is_Base_Type (Id) then Add_Implicit_Operator (Standard_Boolean, Id); return True; end if; Next_Entity (Id); end loop; -- Comparison operators: scalar type, or array of scalar when Name_Op_Lt | Name_Op_Le | Name_Op_Gt | Name_Op_Ge => while Id /= Priv_Id loop if (Is_Scalar_Type (Id) or else (Is_Array_Type (Id) and then Is_Scalar_Type (Component_Type (Id)))) and then Is_Base_Type (Id) then Add_Implicit_Operator (Standard_Boolean, Id); return True; end if; Next_Entity (Id); end loop; -- Arithmetic operators: any numeric type when Name_Op_Abs | Name_Op_Add | Name_Op_Mod | Name_Op_Rem | Name_Op_Subtract | Name_Op_Multiply | Name_Op_Divide | Name_Op_Expon => while Id /= Priv_Id loop if Is_Numeric_Type (Id) and then Is_Base_Type (Id) then Add_Implicit_Operator (Id); return True; end if; Next_Entity (Id); end loop; -- Concatenation: any one-dimensional array type when Name_Op_Concat => while Id /= Priv_Id loop if Is_Array_Type (Id) and then Number_Dimensions (Id) = 1 and then Is_Base_Type (Id) then Add_Implicit_Operator (Id); return True; end if; Next_Entity (Id); end loop; -- What is the others condition here? Should we be using a -- subtype of Name_Id that would restrict to operators ??? when others => null; end case; -- If we fall through, then we do not have an implicit operator return False; end Has_Implicit_Operator; ----------------------------------- -- Has_Loop_In_Inner_Open_Scopes -- ----------------------------------- function Has_Loop_In_Inner_Open_Scopes (S : Entity_Id) return Boolean is begin -- Several scope stacks are maintained by Scope_Stack. The base of the -- currently active scope stack is denoted by the Is_Active_Stack_Base -- flag in the scope stack entry. Note that the scope stacks used to -- simply be delimited implicitly by the presence of Standard_Standard -- at their base, but there now are cases where this is not sufficient -- because Standard_Standard actually may appear in the middle of the -- active set of scopes. for J in reverse 0 .. Scope_Stack.Last loop -- S was reached without seing a loop scope first if Scope_Stack.Table (J).Entity = S then return False; -- S was not yet reached, so it contains at least one inner loop elsif Ekind (Scope_Stack.Table (J).Entity) = E_Loop then return True; end if; -- Check Is_Active_Stack_Base to tell us when to stop, as there are -- cases where Standard_Standard appears in the middle of the active -- set of scopes. This affects the declaration and overriding of -- private inherited operations in instantiations of generic child -- units. pragma Assert (not Scope_Stack.Table (J).Is_Active_Stack_Base); end loop; raise Program_Error; -- unreachable end Has_Loop_In_Inner_Open_Scopes; -------------------- -- In_Open_Scopes -- -------------------- function In_Open_Scopes (S : Entity_Id) return Boolean is begin -- Several scope stacks are maintained by Scope_Stack. The base of the -- currently active scope stack is denoted by the Is_Active_Stack_Base -- flag in the scope stack entry. Note that the scope stacks used to -- simply be delimited implicitly by the presence of Standard_Standard -- at their base, but there now are cases where this is not sufficient -- because Standard_Standard actually may appear in the middle of the -- active set of scopes. for J in reverse 0 .. Scope_Stack.Last loop if Scope_Stack.Table (J).Entity = S then return True; end if; -- Check Is_Active_Stack_Base to tell us when to stop, as there are -- cases where Standard_Standard appears in the middle of the active -- set of scopes. This affects the declaration and overriding of -- private inherited operations in instantiations of generic child -- units. exit when Scope_Stack.Table (J).Is_Active_Stack_Base; end loop; return False; end In_Open_Scopes; ----------------------------- -- Inherit_Renamed_Profile -- ----------------------------- procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id) is New_F : Entity_Id; Old_F : Entity_Id; Old_T : Entity_Id; New_T : Entity_Id; begin if Ekind (Old_S) = E_Operator then New_F := First_Formal (New_S); while Present (New_F) loop Set_Etype (New_F, Base_Type (Etype (New_F))); Next_Formal (New_F); end loop; Set_Etype (New_S, Base_Type (Etype (New_S))); else New_F := First_Formal (New_S); Old_F := First_Formal (Old_S); while Present (New_F) loop New_T := Etype (New_F); Old_T := Etype (Old_F); -- If the new type is a renaming of the old one, as is the -- case for actuals in instances, retain its name, to simplify -- later disambiguation. if Nkind (Parent (New_T)) = N_Subtype_Declaration and then Is_Entity_Name (Subtype_Indication (Parent (New_T))) and then Entity (Subtype_Indication (Parent (New_T))) = Old_T then null; else Set_Etype (New_F, Old_T); end if; Next_Formal (New_F); Next_Formal (Old_F); end loop; if Ekind_In (Old_S, E_Function, E_Enumeration_Literal) then Set_Etype (New_S, Etype (Old_S)); end if; end if; end Inherit_Renamed_Profile; ---------------- -- Initialize -- ---------------- procedure Initialize is begin Urefs.Init; end Initialize; ------------------------- -- Install_Use_Clauses -- ------------------------- procedure Install_Use_Clauses (Clause : Node_Id; Force_Installation : Boolean := False) is U : Node_Id; P : Node_Id; Id : Entity_Id; begin U := Clause; while Present (U) loop -- Case of USE package if Nkind (U) = N_Use_Package_Clause then P := First (Names (U)); while Present (P) loop Id := Entity (P); if Ekind (Id) = E_Package then if In_Use (Id) then Note_Redundant_Use (P); elsif Present (Renamed_Object (Id)) and then In_Use (Renamed_Object (Id)) then Note_Redundant_Use (P); elsif Force_Installation or else Applicable_Use (P) then Use_One_Package (Id, U); end if; end if; Next (P); end loop; -- Case of USE TYPE else P := First (Subtype_Marks (U)); while Present (P) loop if not Is_Entity_Name (P) or else No (Entity (P)) then null; elsif Entity (P) /= Any_Type then Use_One_Type (P); end if; Next (P); end loop; end if; Next_Use_Clause (U); end loop; end Install_Use_Clauses; ------------------------------------- -- Is_Appropriate_For_Entry_Prefix -- ------------------------------------- function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean is P_Type : Entity_Id := T; begin if Is_Access_Type (P_Type) then P_Type := Designated_Type (P_Type); end if; return Is_Task_Type (P_Type) or else Is_Protected_Type (P_Type); end Is_Appropriate_For_Entry_Prefix; ------------------------------- -- Is_Appropriate_For_Record -- ------------------------------- function Is_Appropriate_For_Record (T : Entity_Id) return Boolean is function Has_Components (T1 : Entity_Id) return Boolean; -- Determine if given type has components (i.e. is either a record -- type or a type that has discriminants). -------------------- -- Has_Components -- -------------------- function Has_Components (T1 : Entity_Id) return Boolean is begin return Is_Record_Type (T1) or else (Is_Private_Type (T1) and then Has_Discriminants (T1)) or else (Is_Task_Type (T1) and then Has_Discriminants (T1)) or else (Is_Incomplete_Type (T1) and then From_With_Type (T1) and then Present (Non_Limited_View (T1)) and then Is_Record_Type (Get_Full_View (Non_Limited_View (T1)))); end Has_Components; -- Start of processing for Is_Appropriate_For_Record begin return Present (T) and then (Has_Components (T) or else (Is_Access_Type (T) and then Has_Components (Designated_Type (T)))); end Is_Appropriate_For_Record; ------------------------ -- Note_Redundant_Use -- ------------------------ procedure Note_Redundant_Use (Clause : Node_Id) is Pack_Name : constant Entity_Id := Entity (Clause); Cur_Use : constant Node_Id := Current_Use_Clause (Pack_Name); Decl : constant Node_Id := Parent (Clause); Prev_Use : Node_Id := Empty; Redundant : Node_Id := Empty; -- The Use_Clause which is actually redundant. In the simplest case it -- is Pack itself, but when we compile a body we install its context -- before that of its spec, in which case it is the use_clause in the -- spec that will appear to be redundant, and we want the warning to be -- placed on the body. Similar complications appear when the redundancy -- is between a child unit and one of its ancestors. begin Set_Redundant_Use (Clause, True); if not Comes_From_Source (Clause) or else In_Instance or else not Warn_On_Redundant_Constructs then return; end if; if not Is_Compilation_Unit (Current_Scope) then -- If the use_clause is in an inner scope, it is made redundant by -- some clause in the current context, with one exception: If we're -- compiling a nested package body, and the use_clause comes from the -- corresponding spec, the clause is not necessarily fully redundant, -- so we should not warn. If a warning was warranted, it would have -- been given when the spec was processed. if Nkind (Parent (Decl)) = N_Package_Specification then declare Package_Spec_Entity : constant Entity_Id := Defining_Unit_Name (Parent (Decl)); begin if In_Package_Body (Package_Spec_Entity) then return; end if; end; end if; Redundant := Clause; Prev_Use := Cur_Use; elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then declare Cur_Unit : constant Unit_Number_Type := Get_Source_Unit (Cur_Use); New_Unit : constant Unit_Number_Type := Get_Source_Unit (Clause); Scop : Entity_Id; begin if Cur_Unit = New_Unit then -- Redundant clause in same body Redundant := Clause; Prev_Use := Cur_Use; elsif Cur_Unit = Current_Sem_Unit then -- If the new clause is not in the current unit it has been -- analyzed first, and it makes the other one redundant. -- However, if the new clause appears in a subunit, Cur_Unit -- is still the parent, and in that case the redundant one -- is the one appearing in the subunit. if Nkind (Unit (Cunit (New_Unit))) = N_Subunit then Redundant := Clause; Prev_Use := Cur_Use; -- Most common case: redundant clause in body, -- original clause in spec. Current scope is spec entity. elsif Current_Scope = Defining_Entity ( Unit (Library_Unit (Cunit (Current_Sem_Unit)))) then Redundant := Cur_Use; Prev_Use := Clause; else -- The new clause may appear in an unrelated unit, when -- the parents of a generic are being installed prior to -- instantiation. In this case there must be no warning. -- We detect this case by checking whether the current top -- of the stack is related to the current compilation. Scop := Current_Scope; while Present (Scop) and then Scop /= Standard_Standard loop if Is_Compilation_Unit (Scop) and then not Is_Child_Unit (Scop) then return; elsif Scop = Cunit_Entity (Current_Sem_Unit) then exit; end if; Scop := Scope (Scop); end loop; Redundant := Cur_Use; Prev_Use := Clause; end if; elsif New_Unit = Current_Sem_Unit then Redundant := Clause; Prev_Use := Cur_Use; else -- Neither is the current unit, so they appear in parent or -- sibling units. Warning will be emitted elsewhere. return; end if; end; elsif Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration and then Present (Parent_Spec (Unit (Cunit (Current_Sem_Unit)))) then -- Use_clause is in child unit of current unit, and the child unit -- appears in the context of the body of the parent, so it has been -- installed first, even though it is the redundant one. Depending on -- their placement in the context, the visible or the private parts -- of the two units, either might appear as redundant, but the -- message has to be on the current unit. if Get_Source_Unit (Cur_Use) = Current_Sem_Unit then Redundant := Cur_Use; Prev_Use := Clause; else Redundant := Clause; Prev_Use := Cur_Use; end if; -- If the new use clause appears in the private part of a parent unit -- it may appear to be redundant w.r.t. a use clause in a child unit, -- but the previous use clause was needed in the visible part of the -- child, and no warning should be emitted. if Nkind (Parent (Decl)) = N_Package_Specification and then List_Containing (Decl) = Private_Declarations (Parent (Decl)) then declare Par : constant Entity_Id := Defining_Entity (Parent (Decl)); Spec : constant Node_Id := Specification (Unit (Cunit (Current_Sem_Unit))); begin if Is_Compilation_Unit (Par) and then Par /= Cunit_Entity (Current_Sem_Unit) and then Parent (Cur_Use) = Spec and then List_Containing (Cur_Use) = Visible_Declarations (Spec) then return; end if; end; end if; -- Finally, if the current use clause is in the context then -- the clause is redundant when it is nested within the unit. elsif Nkind (Parent (Cur_Use)) = N_Compilation_Unit and then Nkind (Parent (Parent (Clause))) /= N_Compilation_Unit and then Get_Source_Unit (Cur_Use) = Get_Source_Unit (Clause) then Redundant := Clause; Prev_Use := Cur_Use; else null; end if; if Present (Redundant) then Error_Msg_Sloc := Sloc (Prev_Use); Error_Msg_NE -- CODEFIX ("& is already use-visible through previous use clause #?", Redundant, Pack_Name); end if; end Note_Redundant_Use; --------------- -- Pop_Scope -- --------------- procedure Pop_Scope is SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last); S : constant Entity_Id := SST.Entity; begin if Debug_Flag_E then Write_Info; end if; -- Set Default_Storage_Pool field of the library unit if necessary if Ekind_In (S, E_Package, E_Generic_Package) and then Nkind (Parent (Unit_Declaration_Node (S))) = N_Compilation_Unit then declare Aux : constant Node_Id := Aux_Decls_Node (Parent (Unit_Declaration_Node (S))); begin if No (Default_Storage_Pool (Aux)) then Set_Default_Storage_Pool (Aux, Default_Pool); end if; end; end if; Scope_Suppress := SST.Save_Scope_Suppress; Local_Suppress_Stack_Top := SST.Save_Local_Suppress_Stack_Top; Check_Policy_List := SST.Save_Check_Policy_List; Default_Pool := SST.Save_Default_Storage_Pool; if Debug_Flag_W then Write_Str ("<-- exiting scope: "); Write_Name (Chars (Current_Scope)); Write_Str (", Depth="); Write_Int (Int (Scope_Stack.Last)); Write_Eol; end if; End_Use_Clauses (SST.First_Use_Clause); -- If the actions to be wrapped are still there they will get lost -- causing incomplete code to be generated. It is better to abort in -- this case (and we do the abort even with assertions off since the -- penalty is incorrect code generation) if SST.Actions_To_Be_Wrapped_Before /= No_List or else SST.Actions_To_Be_Wrapped_After /= No_List then raise Program_Error; end if; -- Free last subprogram name if allocated, and pop scope Free (SST.Last_Subprogram_Name); Scope_Stack.Decrement_Last; end Pop_Scope; --------------- -- Push_Scope -- --------------- procedure Push_Scope (S : Entity_Id) is E : constant Entity_Id := Scope (S); begin if Ekind (S) = E_Void then null; -- Set scope depth if not a non-concurrent type, and we have not yet set -- the scope depth. This means that we have the first occurrence of the -- scope, and this is where the depth is set. elsif (not Is_Type (S) or else Is_Concurrent_Type (S)) and then not Scope_Depth_Set (S) then if S = Standard_Standard then Set_Scope_Depth_Value (S, Uint_0); elsif Is_Child_Unit (S) then Set_Scope_Depth_Value (S, Uint_1); elsif not Is_Record_Type (Current_Scope) then if Ekind (S) = E_Loop then Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope)); else Set_Scope_Depth_Value (S, Scope_Depth (Current_Scope) + 1); end if; end if; end if; Scope_Stack.Increment_Last; declare SST : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last); begin SST.Entity := S; SST.Save_Scope_Suppress := Scope_Suppress; SST.Save_Local_Suppress_Stack_Top := Local_Suppress_Stack_Top; SST.Save_Check_Policy_List := Check_Policy_List; SST.Save_Default_Storage_Pool := Default_Pool; if Scope_Stack.Last > Scope_Stack.First then SST.Component_Alignment_Default := Scope_Stack.Table (Scope_Stack.Last - 1). Component_Alignment_Default; end if; SST.Last_Subprogram_Name := null; SST.Is_Transient := False; SST.Node_To_Be_Wrapped := Empty; SST.Pending_Freeze_Actions := No_List; SST.Actions_To_Be_Wrapped_Before := No_List; SST.Actions_To_Be_Wrapped_After := No_List; SST.First_Use_Clause := Empty; SST.Is_Active_Stack_Base := False; SST.Previous_Visibility := False; end; if Debug_Flag_W then Write_Str ("--> new scope: "); Write_Name (Chars (Current_Scope)); Write_Str (", Id="); Write_Int (Int (Current_Scope)); Write_Str (", Depth="); Write_Int (Int (Scope_Stack.Last)); Write_Eol; end if; -- Deal with copying flags from the previous scope to this one. This is -- not necessary if either scope is standard, or if the new scope is a -- child unit. if S /= Standard_Standard and then Scope (S) /= Standard_Standard and then not Is_Child_Unit (S) then if Nkind (E) not in N_Entity then return; end if; -- Copy categorization flags from Scope (S) to S, this is not done -- when Scope (S) is Standard_Standard since propagation is from -- library unit entity inwards. Copy other relevant attributes as -- well (Discard_Names in particular). -- We only propagate inwards for library level entities, -- inner level subprograms do not inherit the categorization. if Is_Library_Level_Entity (S) then Set_Is_Preelaborated (S, Is_Preelaborated (E)); Set_Is_Shared_Passive (S, Is_Shared_Passive (E)); Set_Discard_Names (S, Discard_Names (E)); Set_Suppress_Value_Tracking_On_Call (S, Suppress_Value_Tracking_On_Call (E)); Set_Categorization_From_Scope (E => S, Scop => E); end if; end if; if Is_Child_Unit (S) and then Present (E) and then Ekind_In (E, E_Package, E_Generic_Package) and then Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit then declare Aux : constant Node_Id := Aux_Decls_Node (Parent (Unit_Declaration_Node (E))); begin if Present (Default_Storage_Pool (Aux)) then Default_Pool := Default_Storage_Pool (Aux); end if; end; end if; end Push_Scope; --------------------- -- Premature_Usage -- --------------------- procedure Premature_Usage (N : Node_Id) is Kind : constant Node_Kind := Nkind (Parent (Entity (N))); E : Entity_Id := Entity (N); begin -- Within an instance, the analysis of the actual for a formal object -- does not see the name of the object itself. This is significant only -- if the object is an aggregate, where its analysis does not do any -- name resolution on component associations. (see 4717-008). In such a -- case, look for the visible homonym on the chain. if In_Instance and then Present (Homonym (E)) then E := Homonym (E); while Present (E) and then not In_Open_Scopes (Scope (E)) loop E := Homonym (E); end loop; if Present (E) then Set_Entity (N, E); Set_Etype (N, Etype (E)); return; end if; end if; if Kind = N_Component_Declaration then Error_Msg_N ("component&! cannot be used before end of record declaration", N); elsif Kind = N_Parameter_Specification then Error_Msg_N ("formal parameter&! cannot be used before end of specification", N); elsif Kind = N_Discriminant_Specification then Error_Msg_N ("discriminant&! cannot be used before end of discriminant part", N); elsif Kind = N_Procedure_Specification or else Kind = N_Function_Specification then Error_Msg_N ("subprogram&! cannot be used before end of its declaration", N); elsif Kind = N_Full_Type_Declaration then Error_Msg_N ("type& cannot be used before end of its declaration!", N); else Error_Msg_N ("object& cannot be used before end of its declaration!", N); end if; end Premature_Usage; ------------------------ -- Present_System_Aux -- ------------------------ function Present_System_Aux (N : Node_Id := Empty) return Boolean is Loc : Source_Ptr; Aux_Name : Unit_Name_Type; Unum : Unit_Number_Type; Withn : Node_Id; With_Sys : Node_Id; The_Unit : Node_Id; function Find_System (C_Unit : Node_Id) return Entity_Id; -- Scan context clause of compilation unit to find with_clause -- for System. ----------------- -- Find_System -- ----------------- function Find_System (C_Unit : Node_Id) return Entity_Id is With_Clause : Node_Id; begin With_Clause := First (Context_Items (C_Unit)); while Present (With_Clause) loop if (Nkind (With_Clause) = N_With_Clause and then Chars (Name (With_Clause)) = Name_System) and then Comes_From_Source (With_Clause) then return With_Clause; end if; Next (With_Clause); end loop; return Empty; end Find_System; -- Start of processing for Present_System_Aux begin -- The child unit may have been loaded and analyzed already if Present (System_Aux_Id) then return True; -- If no previous pragma for System.Aux, nothing to load elsif No (System_Extend_Unit) then return False; -- Use the unit name given in the pragma to retrieve the unit. -- Verify that System itself appears in the context clause of the -- current compilation. If System is not present, an error will -- have been reported already. else With_Sys := Find_System (Cunit (Current_Sem_Unit)); The_Unit := Unit (Cunit (Current_Sem_Unit)); if No (With_Sys) and then (Nkind (The_Unit) = N_Package_Body or else (Nkind (The_Unit) = N_Subprogram_Body and then not Acts_As_Spec (Cunit (Current_Sem_Unit)))) then With_Sys := Find_System (Library_Unit (Cunit (Current_Sem_Unit))); end if; if No (With_Sys) and then Present (N) then -- If we are compiling a subunit, we need to examine its -- context as well (Current_Sem_Unit is the parent unit); The_Unit := Parent (N); while Nkind (The_Unit) /= N_Compilation_Unit loop The_Unit := Parent (The_Unit); end loop; if Nkind (Unit (The_Unit)) = N_Subunit then With_Sys := Find_System (The_Unit); end if; end if; if No (With_Sys) then return False; end if; Loc := Sloc (With_Sys); Get_Name_String (Chars (Expression (System_Extend_Unit))); Name_Buffer (8 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len); Name_Buffer (1 .. 7) := "system."; Name_Buffer (Name_Len + 8) := '%'; Name_Buffer (Name_Len + 9) := 's'; Name_Len := Name_Len + 9; Aux_Name := Name_Find; Unum := Load_Unit (Load_Name => Aux_Name, Required => False, Subunit => False, Error_Node => With_Sys); if Unum /= No_Unit then Semantics (Cunit (Unum)); System_Aux_Id := Defining_Entity (Specification (Unit (Cunit (Unum)))); Withn := Make_With_Clause (Loc, Name => Make_Expanded_Name (Loc, Chars => Chars (System_Aux_Id), Prefix => New_Reference_To (Scope (System_Aux_Id), Loc), Selector_Name => New_Reference_To (System_Aux_Id, Loc))); Set_Entity (Name (Withn), System_Aux_Id); Set_Library_Unit (Withn, Cunit (Unum)); Set_Corresponding_Spec (Withn, System_Aux_Id); Set_First_Name (Withn, True); Set_Implicit_With (Withn, True); Insert_After (With_Sys, Withn); Mark_Rewrite_Insertion (Withn); Set_Context_Installed (Withn); return True; -- Here if unit load failed else Error_Msg_Name_1 := Name_System; Error_Msg_Name_2 := Chars (Expression (System_Extend_Unit)); Error_Msg_N ("extension package `%.%` does not exist", Opt.System_Extend_Unit); return False; end if; end if; end Present_System_Aux; ------------------------- -- Restore_Scope_Stack -- ------------------------- procedure Restore_Scope_Stack (Handle_Use : Boolean := True) is E : Entity_Id; S : Entity_Id; Comp_Unit : Node_Id; In_Child : Boolean := False; Full_Vis : Boolean := True; SS_Last : constant Int := Scope_Stack.Last; begin -- Restore visibility of previous scope stack, if any for J in reverse 0 .. Scope_Stack.Last loop exit when Scope_Stack.Table (J).Entity = Standard_Standard or else No (Scope_Stack.Table (J).Entity); S := Scope_Stack.Table (J).Entity; if not Is_Hidden_Open_Scope (S) then -- If the parent scope is hidden, its entities are hidden as -- well, unless the entity is the instantiation currently -- being analyzed. if not Is_Hidden_Open_Scope (Scope (S)) or else not Analyzed (Parent (S)) or else Scope (S) = Standard_Standard then Set_Is_Immediately_Visible (S, True); end if; E := First_Entity (S); while Present (E) loop if Is_Child_Unit (E) then if not From_With_Type (E) then Set_Is_Immediately_Visible (E, Is_Visible_Child_Unit (E) or else In_Open_Scopes (E)); else pragma Assert (Nkind (Parent (E)) = N_Defining_Program_Unit_Name and then Nkind (Parent (Parent (E))) = N_Package_Specification); Set_Is_Immediately_Visible (E, Limited_View_Installed (Parent (Parent (E)))); end if; else Set_Is_Immediately_Visible (E, True); end if; Next_Entity (E); if not Full_Vis and then Is_Package_Or_Generic_Package (S) then -- We are in the visible part of the package scope exit when E = First_Private_Entity (S); end if; end loop; -- The visibility of child units (siblings of current compilation) -- must be restored in any case. Their declarations may appear -- after the private part of the parent. if not Full_Vis then while Present (E) loop if Is_Child_Unit (E) then Set_Is_Immediately_Visible (E, Is_Visible_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 Is_Package_Or_Generic_Package (S) and then (In_Private_Part (S) or else In_Package_Body (S)) then Full_Vis := True; -- if S is the scope of some instance (which has already been -- seen on the stack) it does not affect the visibility of -- other scopes. elsif Is_Hidden_Open_Scope (S) then null; elsif (Ekind (S) = E_Procedure or else Ekind (S) = E_Function) and then Has_Completion (S) then Full_Vis := True; else Full_Vis := False; end if; else Full_Vis := True; end if; end loop; if SS_Last >= Scope_Stack.First and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard and then Handle_Use then Install_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause); end if; end Restore_Scope_Stack; ---------------------- -- Save_Scope_Stack -- ---------------------- procedure Save_Scope_Stack (Handle_Use : Boolean := True) is E : Entity_Id; S : Entity_Id; SS_Last : constant Int := Scope_Stack.Last; begin if SS_Last >= Scope_Stack.First and then Scope_Stack.Table (SS_Last).Entity /= Standard_Standard then if Handle_Use then End_Use_Clauses (Scope_Stack.Table (SS_Last).First_Use_Clause); end if; -- If the call is from within a compilation unit, as when called from -- Rtsfind, make current entries in scope stack invisible while we -- analyze the new unit. for J in reverse 0 .. SS_Last loop exit when Scope_Stack.Table (J).Entity = Standard_Standard or else No (Scope_Stack.Table (J).Entity); S := Scope_Stack.Table (J).Entity; Set_Is_Immediately_Visible (S, False); E := First_Entity (S); while Present (E) loop Set_Is_Immediately_Visible (E, False); Next_Entity (E); end loop; end loop; end if; end Save_Scope_Stack; ------------- -- Set_Use -- ------------- procedure Set_Use (L : List_Id) is Decl : Node_Id; Pack_Name : Node_Id; Pack : Entity_Id; Id : Entity_Id; begin if Present (L) then Decl := First (L); while Present (Decl) loop if Nkind (Decl) = N_Use_Package_Clause then Chain_Use_Clause (Decl); Pack_Name := First (Names (Decl)); while Present (Pack_Name) loop Pack := Entity (Pack_Name); if Ekind (Pack) = E_Package and then Applicable_Use (Pack_Name) then Use_One_Package (Pack, Decl); end if; Next (Pack_Name); end loop; elsif Nkind (Decl) = N_Use_Type_Clause then Chain_Use_Clause (Decl); Id := First (Subtype_Marks (Decl)); while Present (Id) loop if Entity (Id) /= Any_Type then Use_One_Type (Id); end if; Next (Id); end loop; end if; Next (Decl); end loop; end if; end Set_Use; --------------------- -- Use_One_Package -- --------------------- procedure Use_One_Package (P : Entity_Id; N : Node_Id) is Id : Entity_Id; Prev : Entity_Id; Current_Instance : Entity_Id := Empty; Real_P : Entity_Id; Private_With_OK : Boolean := False; begin if Ekind (P) /= E_Package then return; end if; Set_In_Use (P); Set_Current_Use_Clause (P, N); -- Ada 2005 (AI-50217): Check restriction if From_With_Type (P) then Error_Msg_N ("limited withed package cannot appear in use clause", N); end if; -- Find enclosing instance, if any if In_Instance then Current_Instance := Current_Scope; while not Is_Generic_Instance (Current_Instance) loop Current_Instance := Scope (Current_Instance); end loop; if No (Hidden_By_Use_Clause (N)) then Set_Hidden_By_Use_Clause (N, New_Elmt_List); end if; end if; -- If unit is a package renaming, indicate that the renamed -- package is also in use (the flags on both entities must -- remain consistent, and a subsequent use of either of them -- should be recognized as redundant). if Present (Renamed_Object (P)) then Set_In_Use (Renamed_Object (P)); Set_Current_Use_Clause (Renamed_Object (P), N); Real_P := Renamed_Object (P); else Real_P := P; end if; -- Ada 2005 (AI-262): Check the use_clause of a private withed package -- found in the private part of a package specification if In_Private_Part (Current_Scope) and then Has_Private_With (P) and then Is_Child_Unit (Current_Scope) and then Is_Child_Unit (P) and then Is_Ancestor_Package (Scope (Current_Scope), P) then Private_With_OK := True; end if; -- Loop through entities in one package making them potentially -- use-visible. Id := First_Entity (P); while Present (Id) and then (Id /= First_Private_Entity (P) or else Private_With_OK) -- Ada 2005 (AI-262) loop Prev := Current_Entity (Id); while Present (Prev) loop if Is_Immediately_Visible (Prev) and then (not Is_Overloadable (Prev) or else not Is_Overloadable (Id) or else (Type_Conformant (Id, Prev))) then if No (Current_Instance) then -- Potentially use-visible entity remains hidden goto Next_Usable_Entity; -- A use clause within an instance hides outer global entities, -- which are not used to resolve local entities in the -- instance. Note that the predefined entities in Standard -- could not have been hidden in the generic by a use clause, -- and therefore remain visible. Other compilation units whose -- entities appear in Standard must be hidden in an instance. -- To determine whether an entity is external to the instance -- we compare the scope depth of its scope with that of the -- current instance. However, a generic actual of a subprogram -- instance is declared in the wrapper package but will not be -- hidden by a use-visible entity. similarly, an entity that is -- declared in an enclosing instance will not be hidden by an -- an entity declared in a generic actual, which can only have -- been use-visible in the generic and will not have hidden the -- entity in the generic parent. -- If Id is called Standard, the predefined package with the -- same name is in the homonym chain. It has to be ignored -- because it has no defined scope (being the only entity in -- the system with this mandated behavior). elsif not Is_Hidden (Id) and then Present (Scope (Prev)) and then not Is_Wrapper_Package (Scope (Prev)) and then Scope_Depth (Scope (Prev)) < Scope_Depth (Current_Instance) and then (Scope (Prev) /= Standard_Standard or else Sloc (Prev) > Standard_Location) then if In_Open_Scopes (Scope (Prev)) and then Is_Generic_Instance (Scope (Prev)) and then Present (Associated_Formal_Package (P)) then null; else Set_Is_Potentially_Use_Visible (Id); Set_Is_Immediately_Visible (Prev, False); Append_Elmt (Prev, Hidden_By_Use_Clause (N)); end if; end if; -- A user-defined operator is not use-visible if the predefined -- operator for the type is immediately visible, which is the case -- if the type of the operand is in an open scope. This does not -- apply to user-defined operators that have operands of different -- types, because the predefined mixed mode operations (multiply -- and divide) apply to universal types and do not hide anything. elsif Ekind (Prev) = E_Operator and then Operator_Matches_Spec (Prev, Id) and then In_Open_Scopes (Scope (Base_Type (Etype (First_Formal (Id))))) and then (No (Next_Formal (First_Formal (Id))) or else Etype (First_Formal (Id)) = Etype (Next_Formal (First_Formal (Id))) or else Chars (Prev) = Name_Op_Expon) then goto Next_Usable_Entity; -- In an instance, two homonyms may become use_visible through the -- actuals of distinct formal packages. In the generic, only the -- current one would have been visible, so make the other one -- not use_visible. elsif Present (Current_Instance) and then Is_Potentially_Use_Visible (Prev) and then not Is_Overloadable (Prev) and then Scope (Id) /= Scope (Prev) and then Used_As_Generic_Actual (Scope (Prev)) and then Used_As_Generic_Actual (Scope (Id)) and then not In_Same_List (Current_Use_Clause (Scope (Prev)), Current_Use_Clause (Scope (Id))) then Set_Is_Potentially_Use_Visible (Prev, False); Append_Elmt (Prev, Hidden_By_Use_Clause (N)); end if; Prev := Homonym (Prev); end loop; -- On exit, we know entity is not hidden, unless it is private if not Is_Hidden (Id) and then ((not Is_Child_Unit (Id)) or else Is_Visible_Child_Unit (Id)) then Set_Is_Potentially_Use_Visible (Id); if Is_Private_Type (Id) and then Present (Full_View (Id)) then Set_Is_Potentially_Use_Visible (Full_View (Id)); end if; end if; <<Next_Usable_Entity>> Next_Entity (Id); end loop; -- Child units are also made use-visible by a use clause, but they may -- appear after all visible declarations in the parent entity list. while Present (Id) loop if Is_Child_Unit (Id) and then Is_Visible_Child_Unit (Id) then Set_Is_Potentially_Use_Visible (Id); end if; Next_Entity (Id); end loop; if Chars (Real_P) = Name_System and then Scope (Real_P) = Standard_Standard and then Present_System_Aux (N) then Use_One_Package (System_Aux_Id, N); end if; end Use_One_Package; ------------------ -- Use_One_Type -- ------------------ procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False) is Elmt : Elmt_Id; Is_Known_Used : Boolean; Op_List : Elist_Id; T : Entity_Id; function Spec_Reloaded_For_Body return Boolean; -- Determine whether the compilation unit is a package body and the use -- type clause is in the spec of the same package. Even though the spec -- was analyzed first, its context is reloaded when analysing the body. procedure Use_Class_Wide_Operations (Typ : Entity_Id); -- AI05-150: if the use_type_clause carries the "all" qualifier, -- class-wide operations of ancestor types are use-visible if the -- ancestor type is visible. ---------------------------- -- Spec_Reloaded_For_Body -- ---------------------------- function Spec_Reloaded_For_Body return Boolean is begin if Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body then declare Spec : constant Node_Id := Parent (List_Containing (Parent (Id))); begin return Nkind (Spec) = N_Package_Specification and then Corresponding_Body (Parent (Spec)) = Cunit_Entity (Current_Sem_Unit); end; end if; return False; end Spec_Reloaded_For_Body; ------------------------------- -- Use_Class_Wide_Operations -- ------------------------------- procedure Use_Class_Wide_Operations (Typ : Entity_Id) is Scop : Entity_Id; Ent : Entity_Id; function Is_Class_Wide_Operation_Of (Op : Entity_Id; T : Entity_Id) return Boolean; -- Determine whether a subprogram has a class-wide parameter or -- result that is T'Class. --------------------------------- -- Is_Class_Wide_Operation_Of -- --------------------------------- function Is_Class_Wide_Operation_Of (Op : Entity_Id; T : Entity_Id) return Boolean is Formal : Entity_Id; begin Formal := First_Formal (Op); while Present (Formal) loop if Etype (Formal) = Class_Wide_Type (T) then return True; end if; Next_Formal (Formal); end loop; if Etype (Op) = Class_Wide_Type (T) then return True; end if; return False; end Is_Class_Wide_Operation_Of; -- Start of processing for Use_Class_Wide_Operations begin Scop := Scope (Typ); if not Is_Hidden (Scop) then Ent := First_Entity (Scop); while Present (Ent) loop if Is_Overloadable (Ent) and then Is_Class_Wide_Operation_Of (Ent, Typ) and then not Is_Potentially_Use_Visible (Ent) then Set_Is_Potentially_Use_Visible (Ent); Append_Elmt (Ent, Used_Operations (Parent (Id))); end if; Next_Entity (Ent); end loop; end if; if Is_Derived_Type (Typ) then Use_Class_Wide_Operations (Etype (Base_Type (Typ))); end if; end Use_Class_Wide_Operations; -- Start of processing for Use_One_Type begin -- It is the type determined by the subtype mark (8.4(8)) whose -- operations become potentially use-visible. T := Base_Type (Entity (Id)); -- Either the type itself is used, the package where it is declared -- is in use or the entity is declared in the current package, thus -- use-visible. Is_Known_Used := In_Use (T) or else In_Use (Scope (T)) or else Scope (T) = Current_Scope; Set_Redundant_Use (Id, Is_Known_Used or else Is_Potentially_Use_Visible (T)); if Ekind (T) = E_Incomplete_Type then Error_Msg_N ("premature usage of incomplete type", Id); elsif In_Open_Scopes (Scope (T)) then null; -- A limited view cannot appear in a use_type clause. However, an access -- type whose designated type is limited has the flag but is not itself -- a limited view unless we only have a limited view of its enclosing -- package. elsif From_With_Type (T) and then From_With_Type (Scope (T)) then Error_Msg_N ("incomplete type from limited view " & "cannot appear in use clause", Id); -- If the subtype mark designates a subtype in a different package, -- we have to check that the parent type is visible, otherwise the -- use type clause is a noop. Not clear how to do that??? elsif not Redundant_Use (Id) then Set_In_Use (T); -- If T is tagged, primitive operators on class-wide operands -- are also available. if Is_Tagged_Type (T) then Set_In_Use (Class_Wide_Type (T)); end if; Set_Current_Use_Clause (T, Parent (Id)); -- Iterate over primitive operations of the type. If an operation is -- already use_visible, it is the result of a previous use_clause, -- and already appears on the corresponding entity chain. If the -- clause is being reinstalled, operations are already use-visible. if Installed then null; else Op_List := Collect_Primitive_Operations (T); Elmt := First_Elmt (Op_List); while Present (Elmt) loop if (Nkind (Node (Elmt)) = N_Defining_Operator_Symbol or else Chars (Node (Elmt)) in Any_Operator_Name) and then not Is_Hidden (Node (Elmt)) and then not Is_Potentially_Use_Visible (Node (Elmt)) then Set_Is_Potentially_Use_Visible (Node (Elmt)); Append_Elmt (Node (Elmt), Used_Operations (Parent (Id))); elsif Ada_Version >= Ada_2012 and then All_Present (Parent (Id)) and then not Is_Hidden (Node (Elmt)) and then not Is_Potentially_Use_Visible (Node (Elmt)) then Set_Is_Potentially_Use_Visible (Node (Elmt)); Append_Elmt (Node (Elmt), Used_Operations (Parent (Id))); end if; Next_Elmt (Elmt); end loop; end if; if Ada_Version >= Ada_2012 and then All_Present (Parent (Id)) and then Is_Tagged_Type (T) then Use_Class_Wide_Operations (T); end if; end if; -- If warning on redundant constructs, check for unnecessary WITH if Warn_On_Redundant_Constructs and then Is_Known_Used -- with P; with P; use P; -- package P is package X is package body X is -- type T ... use P.T; -- The compilation unit is the body of X. GNAT first compiles the -- spec of X, then proceeds to the body. At that point P is marked -- as use visible. The analysis then reinstalls the spec along with -- its context. The use clause P.T is now recognized as redundant, -- but in the wrong context. Do not emit a warning in such cases. -- Do not emit a warning either if we are in an instance, there is -- no redundancy between an outer use_clause and one that appears -- within the generic. and then not Spec_Reloaded_For_Body and then not In_Instance then -- The type already has a use clause if In_Use (T) then -- Case where we know the current use clause for the type if Present (Current_Use_Clause (T)) then Use_Clause_Known : declare Clause1 : constant Node_Id := Parent (Id); Clause2 : constant Node_Id := Current_Use_Clause (T); Ent1 : Entity_Id; Ent2 : Entity_Id; Err_No : Node_Id; Unit1 : Node_Id; Unit2 : Node_Id; function Entity_Of_Unit (U : Node_Id) return Entity_Id; -- Return the appropriate entity for determining which unit -- has a deeper scope: the defining entity for U, unless U -- is a package instance, in which case we retrieve the -- entity of the instance spec. -------------------- -- Entity_Of_Unit -- -------------------- function Entity_Of_Unit (U : Node_Id) return Entity_Id is begin if Nkind (U) = N_Package_Instantiation and then Analyzed (U) then return Defining_Entity (Instance_Spec (U)); else return Defining_Entity (U); end if; end Entity_Of_Unit; -- Start of processing for Use_Clause_Known begin -- If both current use type clause and the use type clause -- for the type are at the compilation unit level, one of -- the units must be an ancestor of the other, and the -- warning belongs on the descendant. if Nkind (Parent (Clause1)) = N_Compilation_Unit and then Nkind (Parent (Clause2)) = N_Compilation_Unit then -- If the unit is a subprogram body that acts as spec, -- the context clause is shared with the constructed -- subprogram spec. Clearly there is no redundancy. if Clause1 = Clause2 then return; end if; Unit1 := Unit (Parent (Clause1)); Unit2 := Unit (Parent (Clause2)); -- If both clauses are on same unit, or one is the body -- of the other, or one of them is in a subunit, report -- redundancy on the later one. if Unit1 = Unit2 then Error_Msg_Sloc := Sloc (Current_Use_Clause (T)); Error_Msg_NE -- CODEFIX ("& is already use-visible through previous " & "use_type_clause #?", Clause1, T); return; elsif Nkind (Unit1) = N_Subunit then Error_Msg_Sloc := Sloc (Current_Use_Clause (T)); Error_Msg_NE -- CODEFIX ("& is already use-visible through previous " & "use_type_clause #?", Clause1, T); return; elsif Nkind_In (Unit2, N_Package_Body, N_Subprogram_Body) and then Nkind (Unit1) /= Nkind (Unit2) and then Nkind (Unit1) /= N_Subunit then Error_Msg_Sloc := Sloc (Clause1); Error_Msg_NE -- CODEFIX ("& is already use-visible through previous " & "use_type_clause #?", Current_Use_Clause (T), T); return; end if; -- There is a redundant use type clause in a child unit. -- Determine which of the units is more deeply nested. -- If a unit is a package instance, retrieve the entity -- and its scope from the instance spec. Ent1 := Entity_Of_Unit (Unit1); Ent2 := Entity_Of_Unit (Unit2); if Scope (Ent2) = Standard_Standard then Error_Msg_Sloc := Sloc (Current_Use_Clause (T)); Err_No := Clause1; elsif Scope (Ent1) = Standard_Standard then Error_Msg_Sloc := Sloc (Id); Err_No := Clause2; -- If both units are child units, we determine which one -- is the descendant by the scope distance to the -- ultimate parent unit. else declare S1, S2 : Entity_Id; begin S1 := Scope (Ent1); S2 := Scope (Ent2); while Present (S1) and then Present (S2) and then S1 /= Standard_Standard and then S2 /= Standard_Standard loop S1 := Scope (S1); S2 := Scope (S2); end loop; if S1 = Standard_Standard then Error_Msg_Sloc := Sloc (Id); Err_No := Clause2; else Error_Msg_Sloc := Sloc (Current_Use_Clause (T)); Err_No := Clause1; end if; end; end if; Error_Msg_NE -- CODEFIX ("& is already use-visible through previous " & "use_type_clause #?", Err_No, Id); -- Case where current use type clause and the use type -- clause for the type are not both at the compilation unit -- level. In this case we don't have location information. else Error_Msg_NE -- CODEFIX ("& is already use-visible through previous " & "use type clause?", Id, T); end if; end Use_Clause_Known; -- Here if Current_Use_Clause is not set for T, another case -- where we do not have the location information available. else Error_Msg_NE -- CODEFIX ("& is already use-visible through previous " & "use type clause?", Id, T); end if; -- The package where T is declared is already used elsif In_Use (Scope (T)) then Error_Msg_Sloc := Sloc (Current_Use_Clause (Scope (T))); Error_Msg_NE -- CODEFIX ("& is already use-visible through package use clause #?", Id, T); -- The current scope is the package where T is declared else Error_Msg_Node_2 := Scope (T); Error_Msg_NE -- CODEFIX ("& is already use-visible inside package &?", Id, T); end if; end if; end Use_One_Type; ---------------- -- Write_Info -- ---------------- procedure Write_Info is Id : Entity_Id := First_Entity (Current_Scope); begin -- No point in dumping standard entities if Current_Scope = Standard_Standard then return; end if; Write_Str ("========================================================"); Write_Eol; Write_Str (" Defined Entities in "); Write_Name (Chars (Current_Scope)); Write_Eol; Write_Str ("========================================================"); Write_Eol; if No (Id) then Write_Str ("-- none --"); Write_Eol; else while Present (Id) loop Write_Entity_Info (Id, " "); Next_Entity (Id); end loop; end if; if Scope (Current_Scope) = Standard_Standard then -- Print information on the current unit itself Write_Entity_Info (Current_Scope, " "); end if; Write_Eol; end Write_Info; -------- -- ws -- -------- procedure ws is S : Entity_Id; begin for J in reverse 1 .. Scope_Stack.Last loop S := Scope_Stack.Table (J).Entity; Write_Int (Int (S)); Write_Str (" === "); Write_Name (Chars (S)); Write_Eol; end loop; end ws; end Sem_Ch8;