------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M . C H 7 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2005, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package contains the routines to process package specifications and -- bodies. The most important semantic aspects of package processing are the -- handling of private and full declarations, and the construction of -- dispatch tables for tagged types. with Atree; use Atree; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Disp; use Exp_Disp; with Exp_Dbug; use Exp_Dbug; with Lib; use Lib; with Lib.Xref; use Lib.Xref; with Namet; use Namet; with Nmake; use Nmake; with Nlists; use Nlists; with Opt; use Opt; with Output; use Output; with Sem; use Sem; with Sem_Cat; use Sem_Cat; with Sem_Ch3; use Sem_Ch3; with Sem_Ch6; use Sem_Ch6; with Sem_Ch8; use Sem_Ch8; with Sem_Ch10; use Sem_Ch10; with Sem_Ch12; use Sem_Ch12; with Sem_Util; use Sem_Util; with Sem_Warn; use Sem_Warn; with Snames; use Snames; with Stand; use Stand; with Sinfo; use Sinfo; with Sinput; use Sinput; with Style; package body Sem_Ch7 is ----------------------------------- -- 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 the 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. ----------------------- -- Local Subprograms -- ----------------------- procedure Install_Package_Entity (Id : Entity_Id); -- Basic procedure for the previous two. Places one entity on its -- visibility chain, and recurses on the visible part if the entity -- is an inner package. function Is_Private_Base_Type (E : Entity_Id) return Boolean; -- True for a private type that is not a subtype function Is_Visible_Dependent (Dep : Entity_Id) return Boolean; -- If the private dependent is a private type whose full view is -- derived from the parent type, its full properties are revealed -- only if we are in the immediate scope of the private dependent. -- Should this predicate be tightened further??? procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id); -- Called upon entering the private part of a public child package -- and the body of a nested package, to potentially declare certain -- inherited subprograms that were inherited by types in the visible -- part, but whose declaration was deferred because the parent -- operation was private and not visible at that point. These -- subprograms are located by traversing the visible part declarations -- looking for non-private type extensions and then examining each of -- the primitive operations of such types to find those that were -- inherited but declared with a special internal name. Each such -- operation is now declared as an operation with a normal name (using -- the name of the parent operation) and replaces the previous implicit -- operation in the primitive operations list of the type. If the -- inherited private operation has been overridden, then it's -- replaced by the overriding operation. -------------------------- -- Analyze_Package_Body -- -------------------------- procedure Analyze_Package_Body (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); HSS : Node_Id; Body_Id : Entity_Id; Spec_Id : Entity_Id; Last_Spec_Entity : Entity_Id; New_N : Node_Id; Pack_Decl : Node_Id; procedure Install_Composite_Operations (P : Entity_Id); -- Composite types declared in the current scope may depend on -- types that were private at the point of declaration, and whose -- full view is now in scope. Indicate that the corresponding -- operations on the composite type are available. ---------------------------------- -- Install_Composite_Operations -- ---------------------------------- procedure Install_Composite_Operations (P : Entity_Id) is Id : Entity_Id; begin Id := First_Entity (P); while Present (Id) loop if Is_Type (Id) and then (Is_Limited_Composite (Id) or else Is_Private_Composite (Id)) and then No (Private_Component (Id)) then Set_Is_Limited_Composite (Id, False); Set_Is_Private_Composite (Id, False); end if; Next_Entity (Id); end loop; end Install_Composite_Operations; -- Start of processing for Analyze_Package_Body begin -- Find corresponding package specification, and establish the -- current scope. The visible defining entity for the package is the -- defining occurrence in the spec. On exit from the package body, all -- body declarations are attached to the defining entity for the body, -- but the later is never used for name resolution. In this fashion -- there is only one visible entity that denotes the package. if Debug_Flag_C then Write_Str ("==== Compiling package body "); Write_Name (Chars (Defining_Entity (N))); Write_Str (" from "); Write_Location (Loc); Write_Eol; end if; -- Set Body_Id. Note that this Will be reset to point to the -- generic copy later on in the generic case. Body_Id := Defining_Entity (N); if Present (Corresponding_Spec (N)) then -- Body is body of package instantiation. Corresponding spec -- has already been set. Spec_Id := Corresponding_Spec (N); Pack_Decl := Unit_Declaration_Node (Spec_Id); else Spec_Id := Current_Entity_In_Scope (Defining_Entity (N)); if Present (Spec_Id) and then Is_Package (Spec_Id) then Pack_Decl := Unit_Declaration_Node (Spec_Id); if Nkind (Pack_Decl) = N_Package_Renaming_Declaration then Error_Msg_N ("cannot supply body for package renaming", N); return; elsif Present (Corresponding_Body (Pack_Decl)) then Error_Msg_N ("redefinition of package body", N); return; end if; else Error_Msg_N ("missing specification for package body", N); return; end if; if Is_Package (Spec_Id) and then (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id)) and then not Unit_Requires_Body (Spec_Id) then if Ada_Version = Ada_83 then Error_Msg_N ("optional package body (not allowed in Ada 95)?", N); else Error_Msg_N ("spec of this package does not allow a body", N); end if; end if; end if; Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id)); Style.Check_Identifier (Body_Id, Spec_Id); if Is_Child_Unit (Spec_Id) then if Nkind (Parent (N)) /= N_Compilation_Unit then Error_Msg_NE ("body of child unit& cannot be an inner package", N, Spec_Id); end if; Set_Is_Child_Unit (Body_Id); end if; -- Generic package case if Ekind (Spec_Id) = E_Generic_Package then -- Disable expansion and perform semantic analysis on copy. -- The unannotated body will be used in all instantiations. Body_Id := Defining_Entity (N); Set_Ekind (Body_Id, E_Package_Body); Set_Scope (Body_Id, Scope (Spec_Id)); Set_Body_Entity (Spec_Id, Body_Id); Set_Spec_Entity (Body_Id, Spec_Id); New_N := Copy_Generic_Node (N, Empty, Instantiating => False); Rewrite (N, New_N); -- Update Body_Id to point to the copied node for the remainder -- of the processing. Body_Id := Defining_Entity (N); Start_Generic; end if; -- The Body_Id is that of the copied node in the generic case, the -- current node otherwise. Note that N was rewritten above, so we -- must be sure to get the latest Body_Id value. Set_Ekind (Body_Id, E_Package_Body); Set_Body_Entity (Spec_Id, Body_Id); Set_Spec_Entity (Body_Id, Spec_Id); -- Defining name for the package body is not a visible entity: Only -- the defining name for the declaration is visible. Set_Etype (Body_Id, Standard_Void_Type); Set_Scope (Body_Id, Scope (Spec_Id)); Set_Corresponding_Spec (N, Spec_Id); Set_Corresponding_Body (Pack_Decl, Body_Id); -- The body entity is not used for semantics or code generation, but -- it is attached to the entity list of the enclosing scope to simplify -- the listing of back-annotations for the types it main contain. if Scope (Spec_Id) /= Standard_Standard then Append_Entity (Body_Id, Scope (Spec_Id)); end if; -- Indicate that we are currently compiling the body of the package Set_In_Package_Body (Spec_Id); Set_Has_Completion (Spec_Id); Last_Spec_Entity := Last_Entity (Spec_Id); New_Scope (Spec_Id); Set_Categorization_From_Pragmas (N); Install_Visible_Declarations (Spec_Id); Install_Private_Declarations (Spec_Id); Install_Private_With_Clauses (Spec_Id); Install_Composite_Operations (Spec_Id); if Ekind (Spec_Id) = E_Generic_Package then Set_Use (Generic_Formal_Declarations (Pack_Decl)); end if; Set_Use (Visible_Declarations (Specification (Pack_Decl))); Set_Use (Private_Declarations (Specification (Pack_Decl))); -- This is a nested package, so it may be necessary to declare -- certain inherited subprograms that are not yet visible because -- the parent type's subprograms are now visible. if Ekind (Scope (Spec_Id)) = E_Package and then Scope (Spec_Id) /= Standard_Standard then Declare_Inherited_Private_Subprograms (Spec_Id); end if; if Present (Declarations (N)) then Analyze_Declarations (Declarations (N)); end if; HSS := Handled_Statement_Sequence (N); if Present (HSS) then Process_End_Label (HSS, 't', Spec_Id); Analyze (HSS); -- Check that elaboration code in a preelaborable package body is -- empty other than null statements and labels (RM 10.2.1(6)). Validate_Null_Statement_Sequence (N); end if; Validate_Categorization_Dependency (N, Spec_Id); Check_Completion (Body_Id); -- Generate start of body reference. Note that we do this fairly late, -- because the call will use In_Extended_Main_Source_Unit as a check, -- and we want to make sure that Corresponding_Stub links are set Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False); -- For a generic package, collect global references and mark -- them on the original body so that they are not resolved -- again at the point of instantiation. if Ekind (Spec_Id) /= E_Package then Save_Global_References (Original_Node (N)); End_Generic; end if; -- The entities of the package body have so far been chained onto -- the declaration chain for the spec. That's been fine while we -- were in the body, since we wanted them to be visible, but now -- that we are leaving the package body, they are no longer visible, -- so we remove them from the entity chain of the package spec entity, -- and copy them to the entity chain of the package body entity, where -- they will never again be visible. if Present (Last_Spec_Entity) then Set_First_Entity (Body_Id, Next_Entity (Last_Spec_Entity)); Set_Next_Entity (Last_Spec_Entity, Empty); Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); Set_Last_Entity (Spec_Id, Last_Spec_Entity); else Set_First_Entity (Body_Id, First_Entity (Spec_Id)); Set_Last_Entity (Body_Id, Last_Entity (Spec_Id)); Set_First_Entity (Spec_Id, Empty); Set_Last_Entity (Spec_Id, Empty); end if; End_Package_Scope (Spec_Id); -- All entities declared in body are not visible declare E : Entity_Id; begin E := First_Entity (Body_Id); while Present (E) loop Set_Is_Immediately_Visible (E, False); Set_Is_Potentially_Use_Visible (E, False); Set_Is_Hidden (E); -- Child units may appear on the entity list (for example if -- they appear in the context of a subunit) but they are not -- body entities. if not Is_Child_Unit (E) then Set_Is_Package_Body_Entity (E); end if; Next_Entity (E); end loop; end; Check_References (Body_Id); -- For a generic unit, check that the formal parameters are referenced, -- and that local variables are used, as for regular packages. if Ekind (Spec_Id) = E_Generic_Package then Check_References (Spec_Id); end if; -- The processing so far has made all entities of the package body -- public (i.e. externally visible to the linker). This is in general -- necessary, since inlined or generic bodies, for which code is -- generated in other units, may need to see these entities. The -- following loop runs backwards from the end of the entities of the -- package body making these entities invisible until we reach a -- referencer, i.e. a declaration that could reference a previous -- declaration, a generic body or an inlined body, or a stub (which -- may contain either of these). This is of course an approximation, -- but it is conservative and definitely correct. -- We only do this at the outer (library) level non-generic packages. -- The reason is simply to cut down on the number of external symbols -- generated, so this is simply an optimization of the efficiency -- of the compilation process. It has no other effect. if (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id)) and then not Is_Generic_Unit (Spec_Id) and then Present (Declarations (N)) then Make_Non_Public_Where_Possible : declare function Has_Referencer (L : List_Id; Outer : Boolean) return Boolean; -- Traverse the given list of declarations in reverse order. -- Return True as soon as a referencer is reached. Return -- False if none is found. The Outer parameter is True for -- the outer level call, and False for inner level calls for -- nested packages. If Outer is True, then any entities up -- to the point of hitting a referencer get their Is_Public -- flag cleared, so that the entities will be treated as -- static entities in the C sense, and need not have fully -- qualified names. For inner levels, we need all names to -- be fully qualified to deal with the same name appearing -- in parallel packages (right now this is tied to their -- being external). -------------------- -- Has_Referencer -- -------------------- function Has_Referencer (L : List_Id; Outer : Boolean) return Boolean is D : Node_Id; E : Entity_Id; K : Node_Kind; S : Entity_Id; begin if No (L) then return False; end if; D := Last (L); while Present (D) loop K := Nkind (D); if K in N_Body_Stub then return True; elsif K = N_Subprogram_Body then if Acts_As_Spec (D) then E := Defining_Entity (D); -- An inlined body acts as a referencer. Note also -- that we never reset Is_Public for an inlined -- subprogram. Gigi requires Is_Public to be set. -- Note that we test Has_Pragma_Inline here rather -- than Is_Inlined. We are compiling this for a -- client, and it is the client who will decide -- if actual inlining should occur, so we need to -- assume that the procedure could be inlined for -- the purpose of accessing global entities. if Has_Pragma_Inline (E) then return True; else Set_Is_Public (E, False); end if; else E := Corresponding_Spec (D); if Present (E) and then (Is_Generic_Unit (E) or else Has_Pragma_Inline (E) or else Is_Inlined (E)) then return True; end if; end if; -- Processing for package bodies elsif K = N_Package_Body and then Present (Corresponding_Spec (D)) then E := Corresponding_Spec (D); -- Generic package body is a referencer. It would -- seem that we only have to consider generics that -- can be exported, i.e. where the corresponding spec -- is the spec of the current package, but because of -- nested instantiations, a fully private generic -- body may export other private body entities. if Is_Generic_Unit (E) then return True; -- For non-generic package body, recurse into body -- unless this is an instance, we ignore instances -- since they cannot have references that affect -- outer entities. elsif not Is_Generic_Instance (E) then if Has_Referencer (Declarations (D), Outer => False) then return True; end if; end if; -- Processing for package specs, recurse into declarations. -- Again we skip this for the case of generic instances. elsif K = N_Package_Declaration then S := Specification (D); if not Is_Generic_Unit (Defining_Entity (S)) then if Has_Referencer (Private_Declarations (S), Outer => False) then return True; elsif Has_Referencer (Visible_Declarations (S), Outer => False) then return True; end if; end if; -- Objects and exceptions need not be public if we have -- not encountered a referencer so far. We only reset -- the flag for outer level entities that are not -- imported/exported, and which have no interface name. elsif K = N_Object_Declaration or else K = N_Exception_Declaration or else K = N_Subprogram_Declaration then E := Defining_Entity (D); if Outer and then not Is_Imported (E) and then not Is_Exported (E) and then No (Interface_Name (E)) then Set_Is_Public (E, False); end if; end if; Prev (D); end loop; return False; end Has_Referencer; -- Start of processing for Make_Non_Public_Where_Possible begin declare Discard : Boolean; pragma Warnings (Off, Discard); begin Discard := Has_Referencer (Declarations (N), Outer => True); end; end Make_Non_Public_Where_Possible; end if; -- If expander is not active, then here is where we turn off the -- In_Package_Body flag, otherwise it is turned off at the end of -- the corresponding expansion routine. If this is an instance body, -- we need to qualify names of local entities, because the body may -- have been compiled as a preliminary to another instantiation. if not Expander_Active then Set_In_Package_Body (Spec_Id, False); if Is_Generic_Instance (Spec_Id) and then Operating_Mode = Generate_Code then Qualify_Entity_Names (N); end if; end if; end Analyze_Package_Body; --------------------------------- -- Analyze_Package_Declaration -- --------------------------------- procedure Analyze_Package_Declaration (N : Node_Id) is Id : constant Node_Id := Defining_Entity (N); PF : Boolean; begin Generate_Definition (Id); Enter_Name (Id); Set_Ekind (Id, E_Package); Set_Etype (Id, Standard_Void_Type); New_Scope (Id); PF := Is_Pure (Enclosing_Lib_Unit_Entity); Set_Is_Pure (Id, PF); Set_Categorization_From_Pragmas (N); if Debug_Flag_C then Write_Str ("==== Compiling package spec "); Write_Name (Chars (Id)); Write_Str (" from "); Write_Location (Sloc (N)); Write_Eol; end if; Analyze (Specification (N)); Validate_Categorization_Dependency (N, Id); End_Package_Scope (Id); -- For a compilation unit, indicate whether it needs a body, and -- whether elaboration warnings may be meaningful on it. if Nkind (Parent (N)) = N_Compilation_Unit then Set_Body_Required (Parent (N), Unit_Requires_Body (Id)); if not Body_Required (Parent (N)) then Set_Suppress_Elaboration_Warnings (Id); end if; Validate_RT_RAT_Component (N); end if; end Analyze_Package_Declaration; ----------------------------------- -- Analyze_Package_Specification -- ----------------------------------- -- Note that this code is shared for the analysis of generic package -- specs (see Sem_Ch12.Analyze_Generic_Package_Declaration for details). procedure Analyze_Package_Specification (N : Node_Id) is Id : constant Entity_Id := Defining_Entity (N); Orig_Decl : constant Node_Id := Original_Node (Parent (N)); Vis_Decls : constant List_Id := Visible_Declarations (N); Priv_Decls : constant List_Id := Private_Declarations (N); E : Entity_Id; L : Entity_Id; Public_Child : Boolean; procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id); -- Clears constant indications (Never_Set_In_Source, Constant_Value, -- and Is_True_Constant) on all variables that are entities of Id, -- and on the chain whose first element is FE. A recursive call is -- made for all packages and generic packages. procedure Generate_Parent_References; -- For a child unit, generate references to parent units, for -- GPS navigation purposes. function Is_Public_Child (Child, Unit : Entity_Id) return Boolean; -- Child and Unit are entities of compilation units. True if Child -- is a public child of Parent as defined in 10.1.1 procedure Inspect_Deferred_Constant_Completion; -- Examines the deferred constants in the private part of the package -- specification. Emits the error message "constant declaration requires -- initialization expression " if not completed by an Import pragma. procedure Inspect_Unchecked_Union_Completion (Decls : List_Id); -- Detects all incomplete or private type declarations having a known -- discriminant part that are completed by an Unchecked_Union. Emits -- the error message "Unchecked_Union may not complete discriminated -- partial view". --------------------- -- Clear_Constants -- --------------------- procedure Clear_Constants (Id : Entity_Id; FE : Entity_Id) is E : Entity_Id; begin -- Ignore package renamings, not interesting and they can -- cause self referential loops in the code below. if Nkind (Parent (Id)) = N_Package_Renaming_Declaration then return; end if; -- Note: in the loop below, the check for Next_Entity pointing -- back to the package entity seems very odd, but it is needed, -- because this kind of unexpected circularity does occur ??? E := FE; while Present (E) and then E /= Id loop if Ekind (E) = E_Variable then Set_Never_Set_In_Source (E, False); Set_Is_True_Constant (E, False); Set_Current_Value (E, Empty); Set_Is_Known_Non_Null (E, False); elsif Ekind (E) = E_Package or else Ekind (E) = E_Generic_Package then Clear_Constants (E, First_Entity (E)); Clear_Constants (E, First_Private_Entity (E)); end if; Next_Entity (E); end loop; end Clear_Constants; -------------------------------- -- Generate_Parent_References -- -------------------------------- procedure Generate_Parent_References is Decl : constant Node_Id := Parent (N); begin if Id = Cunit_Entity (Main_Unit) or else Parent (Decl) = Library_Unit (Cunit (Main_Unit)) then Generate_Reference (Id, Scope (Id), 'k', False); elsif Nkind (Unit (Cunit (Main_Unit))) /= N_Subprogram_Body and then Nkind (Unit (Cunit (Main_Unit))) /= N_Subunit then -- If current unit is an ancestor of main unit, generate -- a reference to its own parent. declare U : Node_Id; Main_Spec : Node_Id := Unit (Cunit (Main_Unit)); begin if Nkind (Main_Spec) = N_Package_Body then Main_Spec := Unit (Library_Unit (Cunit (Main_Unit))); end if; U := Parent_Spec (Main_Spec); while Present (U) loop if U = Parent (Decl) then Generate_Reference (Id, Scope (Id), 'k', False); exit; elsif Nkind (Unit (U)) = N_Package_Body then exit; else U := Parent_Spec (Unit (U)); end if; end loop; end; end if; end Generate_Parent_References; --------------------- -- Is_Public_Child -- --------------------- function Is_Public_Child (Child, Unit : Entity_Id) return Boolean is begin if not Is_Private_Descendant (Child) then return True; else if Child = Unit then return not Private_Present ( Parent (Unit_Declaration_Node (Child))); else return Is_Public_Child (Scope (Child), Unit); end if; end if; end Is_Public_Child; ------------------------------------------ -- Inspect_Deferred_Constant_Completion -- ------------------------------------------ procedure Inspect_Deferred_Constant_Completion is Decl : Node_Id; begin Decl := First (Priv_Decls); while Present (Decl) loop -- Deferred constant signature if Nkind (Decl) = N_Object_Declaration and then Constant_Present (Decl) and then No (Expression (Decl)) -- No need to check internally generated constants and then Comes_From_Source (Decl) -- The constant is not completed. A full object declaration -- or a pragma Import complete a deferred constant. and then not Has_Completion (Defining_Identifier (Decl)) then Error_Msg_N ("constant declaration requires initialization expression", Defining_Identifier (Decl)); end if; Decl := Next (Decl); end loop; end Inspect_Deferred_Constant_Completion; ---------------------------------------- -- Inspect_Unchecked_Union_Completion -- ---------------------------------------- procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is Decl : Node_Id := First (Decls); begin while Present (Decl) loop -- We are looking at an incomplete or private type declaration -- with a known_discriminant_part whose full view is an -- Unchecked_Union. if (Nkind (Decl) = N_Incomplete_Type_Declaration or else Nkind (Decl) = N_Private_Type_Declaration) and then Has_Discriminants (Defining_Identifier (Decl)) and then Present (Full_View (Defining_Identifier (Decl))) and then Is_Unchecked_Union (Full_View (Defining_Identifier (Decl))) then Error_Msg_N ("completion of discriminated partial view" & " cannot be an Unchecked_Union", Full_View (Defining_Identifier (Decl))); end if; Next (Decl); end loop; end Inspect_Unchecked_Union_Completion; -- Start of processing for Analyze_Package_Specification begin if Present (Vis_Decls) then Analyze_Declarations (Vis_Decls); end if; -- Verify that incomplete types have received full declarations E := First_Entity (Id); while Present (E) loop if Ekind (E) = E_Incomplete_Type and then No (Full_View (E)) then Error_Msg_N ("no declaration in visible part for incomplete}", E); end if; Next_Entity (E); end loop; if Is_Remote_Call_Interface (Id) and then Nkind (Parent (Parent (N))) = N_Compilation_Unit then Validate_RCI_Declarations (Id); end if; -- Save global references in the visible declarations, before -- installing private declarations of parent unit if there is one, -- because the privacy status of types defined in the parent will -- change. This is only relevant for generic child units, but is -- done in all cases for uniformity. if Ekind (Id) = E_Generic_Package and then Nkind (Orig_Decl) = N_Generic_Package_Declaration then declare Orig_Spec : constant Node_Id := Specification (Orig_Decl); Save_Priv : constant List_Id := Private_Declarations (Orig_Spec); begin Set_Private_Declarations (Orig_Spec, Empty_List); Save_Global_References (Orig_Decl); Set_Private_Declarations (Orig_Spec, Save_Priv); end; end if; -- If package is a public child unit, then make the private -- declarations of the parent visible. Public_Child := False; declare Par : Entity_Id; Pack_Decl : Node_Id; Par_Spec : Node_Id; begin Par := Id; Par_Spec := Parent_Spec (Parent (N)); -- If the package is formal package of an enclosing generic, is is -- transformed into a local generic declaration, and compiled to make -- its spec available. We need to retrieve the original generic to -- determine whether it is a child unit, and install its parents. if No (Par_Spec) and then Nkind (Original_Node (Parent (N))) = N_Formal_Package_Declaration then Par := Entity (Name (Original_Node (Parent (N)))); Par_Spec := Parent_Spec (Unit_Declaration_Node (Par)); end if; if Present (Par_Spec) then Generate_Parent_References; while Scope (Par) /= Standard_Standard and then Is_Public_Child (Id, Par) loop Public_Child := True; Par := Scope (Par); Install_Private_Declarations (Par); Install_Private_With_Clauses (Par); Pack_Decl := Unit_Declaration_Node (Par); Set_Use (Private_Declarations (Specification (Pack_Decl))); end loop; end if; end; if Is_Compilation_Unit (Id) then Install_Private_With_Clauses (Id); end if; -- Analyze private part if present. The flag In_Private_Part is -- reset in End_Package_Scope. L := Last_Entity (Id); if Present (Priv_Decls) then Set_In_Private_Part (Id); -- Upon entering a public child's private part, it may be -- necessary to declare subprograms that were derived in -- the package visible part but not yet made visible. if Public_Child then Declare_Inherited_Private_Subprograms (Id); end if; Analyze_Declarations (Priv_Decls); -- Check the private declarations for incomplete deferred constants Inspect_Deferred_Constant_Completion; -- The first private entity is the immediate follower of the last -- visible entity, if there was one. if Present (L) then Set_First_Private_Entity (Id, Next_Entity (L)); else Set_First_Private_Entity (Id, First_Entity (Id)); end if; -- There may be inherited private subprograms that need to be -- declared, even in the absence of an explicit private part. -- If there are any public declarations in the package and -- the package is a public child unit, then an implicit private -- part is assumed. elsif Present (L) and then Public_Child then Set_In_Private_Part (Id); Declare_Inherited_Private_Subprograms (Id); Set_First_Private_Entity (Id, Next_Entity (L)); end if; -- Check rule of 3.6(11), which in general requires -- waiting till all full types have been seen. E := First_Entity (Id); while Present (E) loop if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then Check_Aliased_Component_Types (E); end if; Next_Entity (E); end loop; -- Ada 2005 (AI-216): The completion of an incomplete or private type -- declaration having a known_discriminant_part shall not be an -- Unchecked_Union type. if Present (Vis_Decls) then Inspect_Unchecked_Union_Completion (Vis_Decls); end if; if Present (Priv_Decls) then Inspect_Unchecked_Union_Completion (Priv_Decls); end if; if Ekind (Id) = E_Generic_Package and then Nkind (Orig_Decl) = N_Generic_Package_Declaration and then Present (Priv_Decls) then -- Save global references in private declarations, ignoring the -- visible declarations that were processed earlier. declare Orig_Spec : constant Node_Id := Specification (Orig_Decl); Save_Vis : constant List_Id := Visible_Declarations (Orig_Spec); Save_Form : constant List_Id := Generic_Formal_Declarations (Orig_Decl); begin Set_Visible_Declarations (Orig_Spec, Empty_List); Set_Generic_Formal_Declarations (Orig_Decl, Empty_List); Save_Global_References (Orig_Decl); Set_Generic_Formal_Declarations (Orig_Decl, Save_Form); Set_Visible_Declarations (Orig_Spec, Save_Vis); end; end if; Process_End_Label (N, 'e', Id); -- For the case of a library level package, we must go through all -- the entities clearing the indications that the value may be -- constant and not modified. Why? Because any client of this -- package may modify these values freely from anywhere. This -- also applies to any nested packages or generic packages. -- For now we unconditionally clear constants for packages that -- are instances of generic packages. The reason is that we do not -- have the body yet, and we otherwise think things are unreferenced -- when they are not. This should be fixed sometime (the effect is -- not terrible, we just lose some warnings, and also some cases -- of value propagation) ??? if Is_Library_Level_Entity (Id) or else Is_Generic_Instance (Id) then Clear_Constants (Id, First_Entity (Id)); Clear_Constants (Id, First_Private_Entity (Id)); end if; end Analyze_Package_Specification; -------------------------------------- -- Analyze_Private_Type_Declaration -- -------------------------------------- procedure Analyze_Private_Type_Declaration (N : Node_Id) is PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity); Id : constant Entity_Id := Defining_Identifier (N); begin Generate_Definition (Id); Set_Is_Pure (Id, PF); Init_Size_Align (Id); if (Ekind (Current_Scope) /= E_Package and then Ekind (Current_Scope) /= E_Generic_Package) or else In_Private_Part (Current_Scope) then Error_Msg_N ("invalid context for private declaration", N); end if; New_Private_Type (N, Id, N); Set_Depends_On_Private (Id); end Analyze_Private_Type_Declaration; ------------------------------------------- -- Declare_Inherited_Private_Subprograms -- ------------------------------------------- procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is E : Entity_Id; Op_List : Elist_Id; Op_Elmt : Elmt_Id; Op_Elmt_2 : Elmt_Id; Prim_Op : Entity_Id; New_Op : Entity_Id := Empty; Parent_Subp : Entity_Id; Found_Explicit : Boolean; Decl_Privates : Boolean; function Has_Overriding_Pragma (Subp : Entity_Id) return Boolean; -- Check whether a pragma Overriding has been provided for a primitive -- operation that is found to be overriding in the private part. function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean; -- Check whether an inherited subprogram is an operation of an -- untagged derived type. --------------------------- -- Has_Overriding_Pragma -- --------------------------- function Has_Overriding_Pragma (Subp : Entity_Id) return Boolean is Decl : constant Node_Id := Unit_Declaration_Node (Subp); Prag : Node_Id; begin if No (Decl) or else Nkind (Decl) /= N_Subprogram_Declaration or else No (Next (Decl)) then return False; else Prag := Next (Decl); while Present (Prag) and then Nkind (Prag) = N_Pragma loop if Chars (Prag) = Name_Overriding or else Chars (Prag) = Name_Optional_Overriding then return True; else Next (Prag); end if; end loop; end if; return False; end Has_Overriding_Pragma; --------------------- -- Is_Primitive_Of -- --------------------- function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is Formal : Entity_Id; begin if Etype (S) = T then return True; else Formal := First_Formal (S); while Present (Formal) loop if Etype (Formal) = T then return True; end if; Next_Formal (Formal); end loop; return False; end if; end Is_Primitive_Of; -- Start of processing for Declare_Inherited_Private_Subprograms begin E := First_Entity (Id); while Present (E) loop -- If the entity is a nonprivate type extension whose parent -- type is declared in an open scope, then the type may have -- inherited operations that now need to be made visible. -- Ditto if the entity is a formal derived type in a child unit. if ((Is_Derived_Type (E) and then not Is_Private_Type (E)) or else (Nkind (Parent (E)) = N_Private_Extension_Declaration and then Is_Generic_Type (E))) and then In_Open_Scopes (Scope (Etype (E))) and then E = Base_Type (E) then if Is_Tagged_Type (E) then Op_List := Primitive_Operations (E); New_Op := Empty; Decl_Privates := False; Op_Elmt := First_Elmt (Op_List); while Present (Op_Elmt) loop Prim_Op := Node (Op_Elmt); -- If the primitive operation is an implicit operation -- with an internal name whose parent operation has -- a normal name, then we now need to either declare the -- operation (i.e., make it visible), or replace it -- by an overriding operation if one exists. if Present (Alias (Prim_Op)) and then not Comes_From_Source (Prim_Op) and then Is_Internal_Name (Chars (Prim_Op)) and then not Is_Internal_Name (Chars (Alias (Prim_Op))) then Parent_Subp := Alias (Prim_Op); Found_Explicit := False; Op_Elmt_2 := Next_Elmt (Op_Elmt); while Present (Op_Elmt_2) loop if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp) and then Type_Conformant (Prim_Op, Node (Op_Elmt_2)) then -- The private inherited operation has been -- overridden by an explicit subprogram, so -- change the private op's list element to -- designate the explicit so the explicit -- one will get the right dispatching slot. New_Op := Node (Op_Elmt_2); Replace_Elmt (Op_Elmt, New_Op); Remove_Elmt (Op_List, Op_Elmt_2); Found_Explicit := True; Decl_Privates := True; -- If explicit_overriding is in effect, check that -- the overriding operation is properly labelled. if Explicit_Overriding and then Comes_From_Source (New_Op) and then not Has_Overriding_Pragma (New_Op) then Error_Msg_NE ("Missing overriding pragma for&", New_Op, New_Op); end if; exit; end if; Next_Elmt (Op_Elmt_2); end loop; if not Found_Explicit then Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E)); pragma Assert (Is_Dispatching_Operation (New_Op) and then Node (Last_Elmt (Op_List)) = New_Op); -- Substitute the new operation for the old one -- in the type's primitive operations list. Since -- the new operation was also just added to the end -- of list, the last element must be removed. -- (Question: is there a simpler way of declaring -- the operation, say by just replacing the name -- of the earlier operation, reentering it in the -- in the symbol table (how?), and marking it as -- private???) Replace_Elmt (Op_Elmt, New_Op); Remove_Last_Elmt (Op_List); Decl_Privates := True; end if; end if; Next_Elmt (Op_Elmt); end loop; -- The type's DT attributes need to be recalculated -- in the case where private dispatching operations -- have been added or overridden. Normally this action -- occurs during type freezing, but we force it here -- since the type may already have been frozen (e.g., -- if the type's package has an empty private part). -- This can only be done if expansion is active, otherwise -- Tag may not be present. if Decl_Privates and then Expander_Active then Set_All_DT_Position (E); end if; else -- Non-tagged type, scan forward to locate -- inherited hidden operations. Prim_Op := Next_Entity (E); while Present (Prim_Op) loop if Is_Subprogram (Prim_Op) and then Present (Alias (Prim_Op)) and then not Comes_From_Source (Prim_Op) and then Is_Internal_Name (Chars (Prim_Op)) and then not Is_Internal_Name (Chars (Alias (Prim_Op))) and then Is_Primitive_Of (E, Prim_Op) then Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E)); end if; Next_Entity (Prim_Op); end loop; end if; end if; Next_Entity (E); end loop; end Declare_Inherited_Private_Subprograms; ----------------------- -- End_Package_Scope -- ----------------------- procedure End_Package_Scope (P : Entity_Id) is begin Uninstall_Declarations (P); Pop_Scope; end End_Package_Scope; --------------------------- -- Exchange_Declarations -- --------------------------- procedure Exchange_Declarations (Id : Entity_Id) is Full_Id : constant Entity_Id := Full_View (Id); H1 : constant Entity_Id := Homonym (Id); Next1 : constant Entity_Id := Next_Entity (Id); H2 : Entity_Id; Next2 : Entity_Id; begin -- If missing full declaration for type, nothing to exchange if No (Full_Id) then return; end if; -- Otherwise complete the exchange, and preserve semantic links Next2 := Next_Entity (Full_Id); H2 := Homonym (Full_Id); -- Reset full declaration pointer to reflect the switched entities -- and readjust the next entity chains. Exchange_Entities (Id, Full_Id); Set_Next_Entity (Id, Next1); Set_Homonym (Id, H1); Set_Full_View (Full_Id, Id); Set_Next_Entity (Full_Id, Next2); Set_Homonym (Full_Id, H2); end Exchange_Declarations; ---------------------------- -- Install_Package_Entity -- ---------------------------- procedure Install_Package_Entity (Id : Entity_Id) is begin if not Is_Internal (Id) then if Debug_Flag_E then Write_Str ("Install: "); Write_Name (Chars (Id)); Write_Eol; end if; if not Is_Child_Unit (Id) then Set_Is_Immediately_Visible (Id); end if; end if; end Install_Package_Entity; ---------------------------------- -- Install_Private_Declarations -- ---------------------------------- procedure Install_Private_Declarations (P : Entity_Id) is Id : Entity_Id; Priv_Elmt : Elmt_Id; Priv : Entity_Id; Full : Entity_Id; begin -- First exchange declarations for private types, so that the -- full declaration is visible. For each private type, we check -- its Private_Dependents list and also exchange any subtypes of -- or derived types from it. Finally, if this is a Taft amendment -- type, the incomplete declaration is irrelevant, and we want to -- link the eventual full declaration with the original private -- one so we also skip the exchange. Id := First_Entity (P); while Present (Id) and then Id /= First_Private_Entity (P) loop if Is_Private_Base_Type (Id) and then Comes_From_Source (Full_View (Id)) and then Present (Full_View (Id)) and then Scope (Full_View (Id)) = Scope (Id) and then Ekind (Full_View (Id)) /= E_Incomplete_Type then -- If there is a use-type clause on the private type, set the -- full view accordingly. Set_In_Use (Full_View (Id), In_Use (Id)); Full := Full_View (Id); if Is_Private_Base_Type (Full) and then Has_Private_Declaration (Full) and then Nkind (Parent (Full)) = N_Full_Type_Declaration and then In_Open_Scopes (Scope (Etype (Full))) and then In_Package_Body (Current_Scope) and then not Is_Private_Type (Etype (Full)) then -- This is the completion of a private type by a derivation -- from another private type which is not private anymore. This -- can only happen in a package nested within a child package, -- when the parent type is defined in the parent unit. At this -- point the current type is not private either, and we have to -- install the underlying full view, which is now visible. if No (Full_View (Full)) and then Present (Underlying_Full_View (Full)) then Set_Full_View (Id, Underlying_Full_View (Full)); Set_Underlying_Full_View (Full, Empty); Set_Is_Frozen (Full_View (Id)); end if; end if; Priv_Elmt := First_Elmt (Private_Dependents (Id)); Exchange_Declarations (Id); Set_Is_Immediately_Visible (Id); while Present (Priv_Elmt) loop Priv := Node (Priv_Elmt); -- Before the exchange, verify that the presence of the -- Full_View field. It will be empty if the entity -- has already been installed due to a previous call. if Present (Full_View (Priv)) and then Is_Visible_Dependent (Priv) then -- For each subtype that is swapped, we also swap the -- reference to it in Private_Dependents, to allow access -- to it when we swap them out in End_Package_Scope. Replace_Elmt (Priv_Elmt, Full_View (Priv)); Exchange_Declarations (Priv); Set_Is_Immediately_Visible (Priv, In_Open_Scopes (Scope (Priv))); Set_Is_Potentially_Use_Visible (Priv, Is_Potentially_Use_Visible (Node (Priv_Elmt))); end if; Next_Elmt (Priv_Elmt); end loop; end if; Next_Entity (Id); end loop; -- Next make other declarations in the private part visible as well Id := First_Private_Entity (P); while Present (Id) loop Install_Package_Entity (Id); Set_Is_Hidden (Id, False); Next_Entity (Id); end loop; -- Indicate that the private part is currently visible, so it can be -- properly reset on exit. Set_In_Private_Part (P); end Install_Private_Declarations; ---------------------------------- -- Install_Visible_Declarations -- ---------------------------------- procedure Install_Visible_Declarations (P : Entity_Id) is Id : Entity_Id; begin Id := First_Entity (P); while Present (Id) and then Id /= First_Private_Entity (P) loop Install_Package_Entity (Id); Next_Entity (Id); end loop; end Install_Visible_Declarations; -------------------------- -- Is_Private_Base_Type -- -------------------------- function Is_Private_Base_Type (E : Entity_Id) return Boolean is begin return Ekind (E) = E_Private_Type or else Ekind (E) = E_Limited_Private_Type or else Ekind (E) = E_Record_Type_With_Private; end Is_Private_Base_Type; -------------------------- -- Is_Visible_Dependent -- -------------------------- function Is_Visible_Dependent (Dep : Entity_Id) return Boolean is S : constant Entity_Id := Scope (Dep); begin -- Renamings created for actual types have the visibility of the -- actual. if Ekind (S) = E_Package and then Is_Generic_Instance (S) and then (Is_Generic_Actual_Type (Dep) or else Is_Generic_Actual_Type (Full_View (Dep))) then return True; elsif not (Is_Derived_Type (Dep)) and then Is_Derived_Type (Full_View (Dep)) then -- When instantiating a package body, the scope stack is empty, -- so check instead whether the dependent type is defined in -- the same scope as the instance itself. return In_Open_Scopes (S) or else (Is_Generic_Instance (Current_Scope) and then Scope (Dep) = Scope (Current_Scope)); else return True; end if; end Is_Visible_Dependent; ---------------------------- -- May_Need_Implicit_Body -- ---------------------------- procedure May_Need_Implicit_Body (E : Entity_Id) is P : constant Node_Id := Unit_Declaration_Node (E); S : constant Node_Id := Parent (P); B : Node_Id; Decls : List_Id; begin if not Has_Completion (E) and then Nkind (P) = N_Package_Declaration and then Present (Activation_Chain_Entity (P)) then B := Make_Package_Body (Sloc (E), Defining_Unit_Name => Make_Defining_Identifier (Sloc (E), Chars => Chars (E)), Declarations => New_List); if Nkind (S) = N_Package_Specification then if Present (Private_Declarations (S)) then Decls := Private_Declarations (S); else Decls := Visible_Declarations (S); end if; else Decls := Declarations (S); end if; Append (B, Decls); Analyze (B); end if; end May_Need_Implicit_Body; ---------------------- -- New_Private_Type -- ---------------------- procedure New_Private_Type (N : Node_Id; Id : Entity_Id; Def : Node_Id) is begin Enter_Name (Id); if Limited_Present (Def) then Set_Ekind (Id, E_Limited_Private_Type); else Set_Ekind (Id, E_Private_Type); end if; Set_Etype (Id, Id); Set_Has_Delayed_Freeze (Id); Set_Is_First_Subtype (Id); Init_Size_Align (Id); Set_Is_Constrained (Id, No (Discriminant_Specifications (N)) and then not Unknown_Discriminants_Present (N)); -- Set tagged flag before processing discriminants, to catch -- illegal usage. Set_Is_Tagged_Type (Id, Tagged_Present (Def)); Set_Discriminant_Constraint (Id, No_Elist); Set_Stored_Constraint (Id, No_Elist); if Present (Discriminant_Specifications (N)) then New_Scope (Id); Process_Discriminants (N); End_Scope; elsif Unknown_Discriminants_Present (N) then Set_Has_Unknown_Discriminants (Id); end if; Set_Private_Dependents (Id, New_Elmt_List); if Tagged_Present (Def) then Set_Ekind (Id, E_Record_Type_With_Private); Make_Class_Wide_Type (Id); Set_Primitive_Operations (Id, New_Elmt_List); Set_Is_Abstract (Id, Abstract_Present (Def)); Set_Is_Limited_Record (Id, Limited_Present (Def)); Set_Has_Delayed_Freeze (Id, True); elsif Abstract_Present (Def) then Error_Msg_N ("only a tagged type can be abstract", N); end if; end New_Private_Type; ---------------------------- -- Uninstall_Declarations -- ---------------------------- procedure Uninstall_Declarations (P : Entity_Id) is Decl : constant Node_Id := Unit_Declaration_Node (P); Id : Entity_Id; Full : Entity_Id; Priv_Elmt : Elmt_Id; Priv_Sub : Entity_Id; procedure Preserve_Full_Attributes (Priv, Full : Entity_Id); -- Copy to the private declaration the attributes of the full view -- that need to be available for the partial view also. function Type_In_Use (T : Entity_Id) return Boolean; -- Check whether type or base type appear in an active use_type clause ------------------------------ -- Preserve_Full_Attributes -- ------------------------------ procedure Preserve_Full_Attributes (Priv, Full : Entity_Id) is Priv_Is_Base_Type : constant Boolean := Priv = Base_Type (Priv); begin Set_Size_Info (Priv, (Full)); Set_RM_Size (Priv, RM_Size (Full)); Set_Size_Known_At_Compile_Time (Priv, Size_Known_At_Compile_Time (Full)); Set_Is_Volatile (Priv, Is_Volatile (Full)); Set_Treat_As_Volatile (Priv, Treat_As_Volatile (Full)); if Referenced (Full) then Set_Referenced (Priv); end if; if Priv_Is_Base_Type then Set_Is_Controlled (Priv, Is_Controlled (Base_Type (Full))); Set_Finalize_Storage_Only (Priv, Finalize_Storage_Only (Base_Type (Full))); Set_Has_Task (Priv, Has_Task (Base_Type (Full))); Set_Has_Controlled_Component (Priv, Has_Controlled_Component (Base_Type (Full))); end if; Set_Freeze_Node (Priv, Freeze_Node (Full)); if Is_Tagged_Type (Priv) and then Is_Tagged_Type (Full) and then not Error_Posted (Full) then if Priv_Is_Base_Type then Set_Access_Disp_Table (Priv, Access_Disp_Table (Base_Type (Full))); end if; Set_First_Entity (Priv, First_Entity (Full)); Set_Last_Entity (Priv, Last_Entity (Full)); Set_Has_Discriminants (Priv, Has_Discriminants (Full)); end if; end Preserve_Full_Attributes; ----------------- -- Type_In_Use -- ----------------- function Type_In_Use (T : Entity_Id) return Boolean is begin return Scope (Base_Type (T)) = P and then (In_Use (T) or else In_Use (Base_Type (T))); end Type_In_Use; -- Start of processing for Uninstall_Declarations begin Id := First_Entity (P); while Present (Id) and then Id /= First_Private_Entity (P) loop if Debug_Flag_E then Write_Str ("unlinking visible entity "); Write_Int (Int (Id)); Write_Eol; end if; -- On exit from the package scope, we must preserve the visibility -- established by use clauses in the current scope. Two cases: -- a) If the entity is an operator, it may be a primitive operator of -- a type for which there is a visible use-type clause. -- b) for other entities, their use-visibility is determined by a -- visible use clause for the package itself. For a generic instance, -- the instantiation of the formals appears in the visible part, -- but the formals are private and remain so. if Ekind (Id) = E_Function and then Is_Operator_Symbol_Name (Chars (Id)) and then not Is_Hidden (Id) and then not Error_Posted (Id) then Set_Is_Potentially_Use_Visible (Id, In_Use (P) or else Type_In_Use (Etype (Id)) or else Type_In_Use (Etype (First_Formal (Id))) or else (Present (Next_Formal (First_Formal (Id))) and then Type_In_Use (Etype (Next_Formal (First_Formal (Id)))))); else Set_Is_Potentially_Use_Visible (Id, In_Use (P) and not Is_Hidden (Id)); end if; -- Local entities are not immediately visible outside of the package Set_Is_Immediately_Visible (Id, False); -- If this is a private type with a full view (for example a local -- subtype of a private type declared elsewhere), ensure that the -- full view is also removed from visibility: it may be exposed when -- swapping views in an instantiation. if Is_Type (Id) and then Present (Full_View (Id)) then Set_Is_Immediately_Visible (Full_View (Id), False); end if; if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then Check_Abstract_Overriding (Id); end if; if (Ekind (Id) = E_Private_Type or else Ekind (Id) = E_Limited_Private_Type) and then No (Full_View (Id)) and then not Is_Generic_Type (Id) and then not Is_Derived_Type (Id) then Error_Msg_N ("missing full declaration for private type&", Id); elsif Ekind (Id) = E_Record_Type_With_Private and then not Is_Generic_Type (Id) and then No (Full_View (Id)) then if Nkind (Parent (Id)) = N_Private_Type_Declaration then Error_Msg_N ("missing full declaration for private type&", Id); else Error_Msg_N ("missing full declaration for private extension", Id); end if; elsif Ekind (Id) = E_Constant and then No (Constant_Value (Id)) and then No (Full_View (Id)) and then not Is_Imported (Id) and then (Nkind (Parent (Id)) /= N_Object_Declaration or else not No_Initialization (Parent (Id))) then if not Has_Private_Declaration (Etype (Id)) then -- We assume that the user did not not intend a deferred -- constant declaration, and the expression is just missing. Error_Msg_N ("constant declaration requires initialization expression", Parent (Id)); if Is_Limited_Type (Etype (Id)) then Error_Msg_N ("\else remove keyword CONSTANT from declaration", Parent (Id)); end if; else Error_Msg_N ("missing full declaration for deferred constant ('R'M 7.4)", Id); if Is_Limited_Type (Etype (Id)) then Error_Msg_N ("\else remove keyword CONSTANT from declaration", Parent (Id)); end if; end if; end if; Next_Entity (Id); end loop; -- If the specification was installed as the parent of a public child -- unit, the private declarations were not installed, and there is -- nothing to do. if not In_Private_Part (P) then return; else Set_In_Private_Part (P, False); end if; -- Make private entities invisible and exchange full and private -- declarations for private types. while Present (Id) loop if Debug_Flag_E then Write_Str ("unlinking private entity "); Write_Int (Int (Id)); Write_Eol; end if; if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then Check_Abstract_Overriding (Id); end if; Set_Is_Immediately_Visible (Id, False); if Is_Private_Base_Type (Id) and then Present (Full_View (Id)) then Full := Full_View (Id); -- If the partial view is not declared in the visible part -- of the package (as is the case when it is a type derived -- from some other private type in the private part of the -- current package), no exchange takes place. if No (Parent (Id)) or else List_Containing (Parent (Id)) /= Visible_Declarations (Specification (Decl)) then goto Next_Id; end if; -- The entry in the private part points to the full declaration, -- which is currently visible. Exchange them so only the private -- type declaration remains accessible, and link private and -- full declaration in the opposite direction. Before the actual -- exchange, we copy back attributes of the full view that -- must be available to the partial view too. Preserve_Full_Attributes (Id, Full); Set_Is_Potentially_Use_Visible (Id, In_Use (P)); if Is_Indefinite_Subtype (Full) and then not Is_Indefinite_Subtype (Id) then Error_Msg_N ("full view of type must be definite subtype", Full); end if; Priv_Elmt := First_Elmt (Private_Dependents (Id)); -- Swap out the subtypes and derived types of Id that were -- compiled in this scope, or installed previously by -- Install_Private_Declarations. -- Before we do the swap, we verify the presence of the -- Full_View field which may be empty due to a swap by -- a previous call to End_Package_Scope (e.g. from the -- freezing mechanism). while Present (Priv_Elmt) loop Priv_Sub := Node (Priv_Elmt); if Present (Full_View (Priv_Sub)) then if Scope (Priv_Sub) = P or else not In_Open_Scopes (Scope (Priv_Sub)) then Set_Is_Immediately_Visible (Priv_Sub, False); end if; if Is_Visible_Dependent (Priv_Sub) then Preserve_Full_Attributes (Priv_Sub, Full_View (Priv_Sub)); Replace_Elmt (Priv_Elmt, Full_View (Priv_Sub)); Exchange_Declarations (Priv_Sub); end if; end if; Next_Elmt (Priv_Elmt); end loop; -- Now restore the type itself to its private view. Exchange_Declarations (Id); elsif Ekind (Id) = E_Incomplete_Type and then No (Full_View (Id)) then -- Mark Taft amendment types Set_Has_Completion_In_Body (Id); elsif not Is_Child_Unit (Id) and then (not Is_Private_Type (Id) or else No (Full_View (Id))) then Set_Is_Hidden (Id); Set_Is_Potentially_Use_Visible (Id, False); end if; <> Next_Entity (Id); end loop; end Uninstall_Declarations; ------------------------ -- Unit_Requires_Body -- ------------------------ function Unit_Requires_Body (P : Entity_Id) return Boolean is E : Entity_Id; begin -- Imported entity never requires body. Right now, only -- subprograms can be imported, but perhaps in the future -- we will allow import of packages. if Is_Imported (P) then return False; -- Body required if library package with pragma Elaborate_Body elsif Has_Pragma_Elaborate_Body (P) then return True; -- Body required if subprogram elsif Is_Subprogram (P) or else Is_Generic_Subprogram (P) then return True; -- Treat a block as requiring a body elsif Ekind (P) = E_Block then return True; elsif Ekind (P) = E_Package and then Nkind (Parent (P)) = N_Package_Specification and then Present (Generic_Parent (Parent (P))) then declare G_P : constant Entity_Id := Generic_Parent (Parent (P)); begin if Has_Pragma_Elaborate_Body (G_P) then return True; end if; end; end if; -- Otherwise search entity chain for entity requiring completion E := First_Entity (P); while Present (E) loop -- Always ignore child units. Child units get added to the entity -- list of a parent unit, but are not original entities of the -- parent, and so do not affect whether the parent needs a body. if Is_Child_Unit (E) then null; -- Ignore formal packages and their renamings elsif Ekind (E) = E_Package and then Nkind (Original_Node (Unit_Declaration_Node (E))) = N_Formal_Package_Declaration then null; -- Otherwise test to see if entity requires a completion elsif (Is_Overloadable (E) and then Ekind (E) /= E_Enumeration_Literal and then Ekind (E) /= E_Operator and then not Is_Abstract (E) and then not Has_Completion (E)) or else (Ekind (E) = E_Package and then E /= P and then not Has_Completion (E) and then Unit_Requires_Body (E)) or else (Ekind (E) = E_Incomplete_Type and then No (Full_View (E))) or else ((Ekind (E) = E_Task_Type or else Ekind (E) = E_Protected_Type) and then not Has_Completion (E)) or else (Ekind (E) = E_Generic_Package and then E /= P and then not Has_Completion (E) and then Unit_Requires_Body (E)) or else (Is_Generic_Subprogram (E) and then not Has_Completion (E)) then return True; -- Entity that does not require completion else null; end if; Next_Entity (E); end loop; return False; end Unit_Requires_Body; end Sem_Ch7;