------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 7 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2017, 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. -- -- -- ------------------------------------------------------------------------------ -- 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 Aspects; use Aspects; with Atree; use Atree; with Contracts; use Contracts; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Disp; use Exp_Disp; with Exp_Dist; use Exp_Dist; with Exp_Dbug; use Exp_Dbug; with Freeze; use Freeze; with Ghost; use Ghost; 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 Restrict; use Restrict; 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_Ch6; use Sem_Ch6; with Sem_Ch8; use Sem_Ch8; with Sem_Ch10; use Sem_Ch10; with Sem_Ch12; use Sem_Ch12; with Sem_Ch13; use Sem_Ch13; with Sem_Disp; use Sem_Disp; with Sem_Eval; use Sem_Eval; with Sem_Prag; use Sem_Prag; 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; with Uintp; use Uintp; with GNAT.HTable; 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 Analyze_Package_Body_Helper (N : Node_Id); -- Does all the real work of Analyze_Package_Body procedure Check_Anonymous_Access_Types (Spec_Id : Entity_Id; P_Body : Node_Id); -- If the spec of a package has a limited_with_clause, it may declare -- anonymous access types whose designated type is a limited view, such an -- anonymous access return type for a function. This access type cannot be -- elaborated in the spec itself, but it may need an itype reference if it -- is used within a nested scope. In that case the itype reference is -- created at the beginning of the corresponding package body and inserted -- before other body declarations. 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. procedure Install_Package_Entity (Id : Entity_Id); -- Supporting procedure for Install_{Visible,Private}_Declarations. 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??? function Requires_Completion_In_Body (Id : Entity_Id; Pack_Id : Entity_Id; Do_Abstract_States : Boolean := False) return Boolean; -- Subsidiary to routines Unit_Requires_Body and Unit_Requires_Body_Info. -- Determine whether entity Id declared in package spec Pack_Id requires -- completion in a package body. Flag Do_Abstract_Stats should be set when -- abstract states are to be considered in the completion test. procedure Unit_Requires_Body_Info (Pack_Id : Entity_Id); -- Outputs info messages showing why package Pack_Id requires a body. The -- caller has checked that the switch requesting this information is set, -- and that the package does indeed require a body. -------------------------- -- Analyze_Package_Body -- -------------------------- procedure Analyze_Package_Body (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); begin if Debug_Flag_C then Write_Str ("==> package body "); Write_Name (Chars (Defining_Entity (N))); Write_Str (" from "); Write_Location (Loc); Write_Eol; Indent; end if; -- The real work is split out into the helper, so it can do "return;" -- without skipping the debug output. Analyze_Package_Body_Helper (N); if Debug_Flag_C then Outdent; Write_Str ("<== package body "); Write_Name (Chars (Defining_Entity (N))); Write_Str (" from "); Write_Location (Loc); Write_Eol; end if; end Analyze_Package_Body; ------------------------------------------------------ -- Analyze_Package_Body_Helper Data and Subprograms -- ------------------------------------------------------ Entity_Table_Size : constant := 4093; -- Number of headers in hash table subtype Entity_Header_Num is Integer range 0 .. Entity_Table_Size - 1; -- Range of headers in hash table function Node_Hash (Id : Entity_Id) return Entity_Header_Num; -- Simple hash function for Entity_Ids package Subprogram_Table is new GNAT.Htable.Simple_HTable (Header_Num => Entity_Header_Num, Element => Boolean, No_Element => False, Key => Entity_Id, Hash => Node_Hash, Equal => "="); -- Hash table to record which subprograms are referenced. It is declared -- at library level to avoid elaborating it for every call to Analyze. package Traversed_Table is new GNAT.Htable.Simple_HTable (Header_Num => Entity_Header_Num, Element => Boolean, No_Element => False, Key => Node_Id, Hash => Node_Hash, Equal => "="); -- Hash table to record which nodes we have traversed, so we can avoid -- traversing the same nodes repeatedly. ----------------- -- Node_Hash -- ----------------- function Node_Hash (Id : Entity_Id) return Entity_Header_Num is begin return Entity_Header_Num (Id mod Entity_Table_Size); end Node_Hash; --------------------------------- -- Analyze_Package_Body_Helper -- --------------------------------- -- WARNING: This routine manages Ghost regions. Return statements must be -- replaced by gotos which jump to the end of the routine and restore the -- Ghost mode. procedure Analyze_Package_Body_Helper (N : Node_Id) is procedure Hide_Public_Entities (Decls : List_Id); -- Attempt to hide all public entities found in declarative list Decls -- by resetting their Is_Public flag to False depending on whether the -- entities are not referenced by inlined or generic bodies. This kind -- of processing is a conservative approximation and will still leave -- entities externally visible if the package is not simple enough. 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. -------------------------- -- Hide_Public_Entities -- -------------------------- procedure Hide_Public_Entities (Decls : List_Id) is function Has_Referencer (Decls : List_Id; Top_Level : Boolean := False) return Boolean; -- A "referencer" is a construct which may reference a previous -- declaration. Examine all declarations in list Decls in reverse -- and determine whether once such referencer exists. All entities -- in the range Last (Decls) .. Referencer are hidden from external -- visibility. function Scan_Subprogram_Ref (N : Node_Id) return Traverse_Result; -- Determine whether a node denotes a reference to a subprogram procedure Traverse_And_Scan_Subprogram_Refs is new Traverse_Proc (Scan_Subprogram_Ref); -- Subsidiary to routine Has_Referencer. Determine whether a node -- contains references to a subprogram and record them. -- WARNING: this is a very expensive routine as it performs a full -- tree traversal. procedure Scan_Subprogram_Refs (Node : Node_Id); -- If we haven't already traversed Node, then mark it and traverse -- it. -------------------- -- Has_Referencer -- -------------------- function Has_Referencer (Decls : List_Id; Top_Level : Boolean := False) return Boolean is Decl : Node_Id; Decl_Id : Entity_Id; Spec : Node_Id; Has_Non_Subprograms_Referencer : Boolean := False; -- Set if an inlined subprogram body was detected as a referencer. -- In this case, we do not return True immediately but keep hiding -- subprograms from external visibility. begin if No (Decls) then return False; end if; -- Examine all declarations in reverse order, hiding all entities -- from external visibility until a referencer has been found. The -- algorithm recurses into nested packages. Decl := Last (Decls); while Present (Decl) loop -- A stub is always considered a referencer if Nkind (Decl) in N_Body_Stub then return True; -- Package declaration elsif Nkind (Decl) = N_Package_Declaration then Spec := Specification (Decl); -- Inspect the declarations of a non-generic package to try -- and hide more entities from external visibility. if not Is_Generic_Unit (Defining_Entity (Spec)) then if Has_Referencer (Private_Declarations (Spec)) or else Has_Referencer (Visible_Declarations (Spec)) then return True; end if; end if; -- Package body elsif Nkind (Decl) = N_Package_Body and then Present (Corresponding_Spec (Decl)) then Decl_Id := Corresponding_Spec (Decl); -- A 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. Furthermore, regardless of -- whether there was a previous inlined subprogram, (an -- instantiation of) the generic package may reference any -- entity declared before it. if Is_Generic_Unit (Decl_Id) then return True; -- Inspect the declarations of a non-generic package body to -- try and hide more entities from external visibility. elsif Has_Referencer (Declarations (Decl)) then return True; end if; -- Subprogram body elsif Nkind (Decl) = N_Subprogram_Body then if Present (Corresponding_Spec (Decl)) then Decl_Id := Corresponding_Spec (Decl); -- A generic subprogram body acts as a referencer if Is_Generic_Unit (Decl_Id) then return True; end if; -- An inlined subprogram body acts as a referencer -- Note that we test Has_Pragma_Inline here in addition -- to Is_Inlined. We are doing this for a client, since -- we are computing which entities should be public, and -- it is the client who will decide if actual inlining -- should occur, so we need to catch all cases where the -- subprogram may be inlined by the client. if Is_Inlined (Decl_Id) or else Has_Pragma_Inline (Decl_Id) then Has_Non_Subprograms_Referencer := True; -- Inspect the statements of the subprogram body -- to determine whether the body references other -- subprograms. Scan_Subprogram_Refs (Decl); end if; -- Otherwise this is a stand alone subprogram body else Decl_Id := Defining_Entity (Decl); -- An inlined subprogram body acts as a referencer if Is_Inlined (Decl_Id) or else Has_Pragma_Inline (Decl_Id) then Has_Non_Subprograms_Referencer := True; -- Inspect the statements of the subprogram body -- to determine whether the body references other -- subprograms. Scan_Subprogram_Refs (Decl); -- Otherwise we can reset Is_Public right away elsif not Subprogram_Table.Get (Decl_Id) then Set_Is_Public (Decl_Id, False); end if; end if; -- Freeze node elsif Nkind (Decl) = N_Freeze_Entity then declare Discard : Boolean; pragma Unreferenced (Discard); begin -- Inspect the actions to find references to subprograms Discard := Has_Referencer (Actions (Decl)); end; -- Exceptions, objects and renamings do not need to be public -- if they are not followed by a construct which can reference -- and export them. The Is_Public flag is reset on top level -- entities only as anything nested is local to its context. -- Likewise for subprograms, but we work harder for them. elsif Nkind_In (Decl, N_Exception_Declaration, N_Object_Declaration, N_Object_Renaming_Declaration, N_Subprogram_Declaration, N_Subprogram_Renaming_Declaration) then Decl_Id := Defining_Entity (Decl); if Top_Level and then not Is_Imported (Decl_Id) and then not Is_Exported (Decl_Id) and then No (Interface_Name (Decl_Id)) and then (not Has_Non_Subprograms_Referencer or else (Nkind (Decl) = N_Subprogram_Declaration and then not Subprogram_Table.Get (Decl_Id))) then Set_Is_Public (Decl_Id, False); end if; -- For a subprogram renaming, if the entity is referenced, -- then so is the renamed subprogram. But there is an issue -- with generic bodies because instantiations are not done -- yet and, therefore, cannot be scanned for referencers. -- That's why we use an approximation and test that we have -- at least one subprogram referenced by an inlined body -- instead of precisely the entity of this renaming. if Nkind (Decl) = N_Subprogram_Renaming_Declaration and then Subprogram_Table.Get_First and then Is_Entity_Name (Name (Decl)) and then Present (Entity (Name (Decl))) and then Is_Subprogram (Entity (Name (Decl))) then Subprogram_Table.Set (Entity (Name (Decl)), True); end if; end if; Prev (Decl); end loop; return Has_Non_Subprograms_Referencer; end Has_Referencer; ------------------------- -- Scan_Subprogram_Ref -- ------------------------- function Scan_Subprogram_Ref (N : Node_Id) return Traverse_Result is begin -- Detect a reference of the form -- Subp_Call if Nkind (N) in N_Subprogram_Call and then Is_Entity_Name (Name (N)) and then Present (Entity (Name (N))) and then Is_Subprogram (Entity (Name (N))) then Subprogram_Table.Set (Entity (Name (N)), True); -- Detect a reference of the form -- Subp'Some_Attribute elsif Nkind (N) = N_Attribute_Reference and then Is_Entity_Name (Prefix (N)) and then Present (Entity (Prefix (N))) and then Is_Subprogram (Entity (Prefix (N))) then Subprogram_Table.Set (Entity (Prefix (N)), True); -- Constants can be substituted by their value in gigi, which may -- contain a reference, so scan the value recursively. elsif Is_Entity_Name (N) and then Present (Entity (N)) and then Ekind (Entity (N)) = E_Constant then declare Val : constant Node_Id := Constant_Value (Entity (N)); begin if Present (Val) and then not Compile_Time_Known_Value (Val) then Scan_Subprogram_Refs (Val); end if; end; end if; return OK; end Scan_Subprogram_Ref; -------------------------- -- Scan_Subprogram_Refs -- -------------------------- procedure Scan_Subprogram_Refs (Node : Node_Id) is begin if not Traversed_Table.Get (Node) then Traversed_Table.Set (Node, True); Traverse_And_Scan_Subprogram_Refs (Node); end if; end Scan_Subprogram_Refs; -- Local variables Discard : Boolean; pragma Unreferenced (Discard); -- Start of processing for Hide_Public_Entities begin -- The algorithm examines the top level declarations of a package -- body in reverse looking for a construct that may export entities -- declared prior to it. If such a scenario is encountered, then all -- entities in the range Last (Decls) .. construct are hidden from -- external visibility. Consider: -- package Pack is -- generic -- package Gen is -- end Gen; -- end Pack; -- package body Pack is -- External_Obj : ...; -- (1) -- package body Gen is -- (2) -- ... External_Obj ... -- (3) -- end Gen; -- Local_Obj : ...; -- (4) -- end Pack; -- In this example Local_Obj (4) must not be externally visible as -- it cannot be exported by anything in Pack. The body of generic -- package Gen (2) on the other hand acts as a "referencer" and may -- export anything declared before it. Since the compiler does not -- perform flow analysis, it is not possible to determine precisely -- which entities will be exported when Gen is instantiated. In the -- example above External_Obj (1) is exported at (3), but this may -- not always be the case. The algorithm takes a conservative stance -- and leaves entity External_Obj public. -- This very conservative algorithm is supplemented by a more precise -- processing for inlined bodies. For them, we traverse the syntactic -- tree and record which subprograms are actually referenced from it. -- This makes it possible to compute a much smaller set of externally -- visible subprograms in the absence of generic bodies, which can -- have a significant impact on the inlining decisions made in the -- back end and the removal of out-of-line bodies from the object -- code. We do it only for inlined bodies because they are supposed -- to be reasonably small and tree traversal is very expensive. -- Note that even this special processing is not optimal for inlined -- bodies, because we treat all inlined subprograms alike. An optimal -- algorithm would require computing the transitive closure of the -- inlined subprograms that can really be referenced from other units -- in the source code. -- We could extend this processing for inlined bodies and record all -- entities, not just subprograms, referenced from them, which would -- make it possible to compute a much smaller set of all externally -- visible entities in the absence of generic bodies. But this would -- mean implementing a more thorough tree traversal of the bodies, -- i.e. not just syntactic, and the gain would very likely be worth -- neither the hassle nor the slowdown of the compiler. -- Finally, an important thing to be aware of is that, at this point, -- instantiations are not done yet so we cannot directly see inlined -- bodies coming from them. That's not catastrophic because only the -- actual parameters of the instantiations matter here, and they are -- present in the declarations list of the instantiated packages. Traversed_Table.Reset; Subprogram_Table.Reset; Discard := Has_Referencer (Decls, Top_Level => True); end Hide_Public_Entities; ---------------------------------- -- 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; -- Local variables Saved_GM : constant Ghost_Mode_Type := Ghost_Mode; Saved_ISMP : constant Boolean := Ignore_SPARK_Mode_Pragmas_In_Instance; -- Save the Ghost and SPARK mode-related data to restore on exit Body_Id : Entity_Id; HSS : Node_Id; Last_Spec_Entity : Entity_Id; New_N : Node_Id; Pack_Decl : Node_Id; Spec_Id : Entity_Id; -- Start of processing for Analyze_Package_Body_Helper 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. -- 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); -- Body is body of package instantiation. Corresponding spec has already -- been set. if Present (Corresponding_Spec (N)) then 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_Or_Generic_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_Or_Generic_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; -- A [generic] package body freezes the contract of the nearest -- enclosing package body and all other contracts encountered in -- the same declarative part up to and excluding the package body: -- package body Nearest_Enclosing_Package -- with Refined_State => (State => Constit) -- is -- Constit : ...; -- package body Freezes_Enclosing_Package_Body -- with Refined_State => (State_2 => Constit_2) -- is -- Constit_2 : ...; -- procedure Proc -- with Refined_Depends => (Input => (Constit, Constit_2)) ... -- This ensures that any annotations referenced by the contract of a -- [generic] subprogram body declared within the current package body -- are available. This form of freezing is decoupled from the usual -- Freeze_xxx mechanism because it must also work in the context of -- generics where normal freezing is disabled. -- Only bodies coming from source should cause this type of freezing. -- Instantiated generic bodies are excluded because their processing is -- performed in a separate compilation pass which lacks enough semantic -- information with respect to contract analysis. It is safe to suppress -- the freezing of contracts in this case because this action already -- took place at the end of the enclosing declarative part. if Comes_From_Source (N) and then not Is_Generic_Instance (Spec_Id) then Freeze_Previous_Contracts (N); end if; -- A package body is Ghost when the corresponding spec is Ghost. Set -- the mode now to ensure that any nodes generated during analysis and -- expansion are properly flagged as ignored Ghost. Mark_And_Set_Ghost_Body (N, Spec_Id); 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_Is_Obsolescent (Body_Id, Is_Obsolescent (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); -- Once the contents of the generic copy and the template are -- swapped, do the same for their respective aspect specifications. Exchange_Aspects (N, New_N); -- Collect all contract-related source pragmas found within the -- template and attach them to the contract of the package body. -- This contract is used in the capture of global references within -- annotations. Create_Generic_Contract (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); if Has_Aspects (N) then Analyze_Aspect_Specifications (N, Body_Id); end if; Push_Scope (Spec_Id); -- Set SPARK_Mode only for non-generic package if Ekind (Spec_Id) = E_Package then Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma); Set_SPARK_Aux_Pragma (Body_Id, SPARK_Mode_Pragma); Set_SPARK_Pragma_Inherited (Body_Id); Set_SPARK_Aux_Pragma_Inherited (Body_Id); -- A package body may be instantiated or inlined at a later pass. -- Restore the state of Ignore_SPARK_Mode_Pragmas_In_Instance when -- it applied to the package spec. if Ignore_SPARK_Mode_Pragmas (Spec_Id) then Ignore_SPARK_Mode_Pragmas_In_Instance := True; end if; end if; 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); Check_Anonymous_Access_Types (Spec_Id, N); 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)); Inspect_Deferred_Constant_Completion (Declarations (N)); end if; -- Verify that the SPARK_Mode of the body agrees with that of its spec if Present (SPARK_Pragma (Body_Id)) then if Present (SPARK_Aux_Pragma (Spec_Id)) then if Get_SPARK_Mode_From_Annotation (SPARK_Aux_Pragma (Spec_Id)) = Off and then Get_SPARK_Mode_From_Annotation (SPARK_Pragma (Body_Id)) = On then Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); Error_Msg_N ("incorrect application of SPARK_Mode#", N); Error_Msg_Sloc := Sloc (SPARK_Aux_Pragma (Spec_Id)); Error_Msg_NE ("\value Off was set for SPARK_Mode on & #", N, Spec_Id); end if; else Error_Msg_Sloc := Sloc (SPARK_Pragma (Body_Id)); Error_Msg_N ("incorrect application of SPARK_Mode#", N); Error_Msg_Sloc := Sloc (Spec_Id); Error_Msg_NE ("\no value was set for SPARK_Mode on & #", N, Spec_Id); end if; end if; -- Analyze_Declarations has caused freezing of all types. Now generate -- bodies for RACW primitives and stream attributes, if any. if Ekind (Spec_Id) = E_Package and then Has_RACW (Spec_Id) then -- Attach subprogram bodies to support RACWs declared in spec Append_RACW_Bodies (Declarations (N), Spec_Id); Analyze_List (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; Update_Use_Clause_Chain; 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 (e.g. 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; -- At this point all entities of the package body are externally visible -- to the linker as their Is_Public flag is set to True. This proactive -- approach is necessary because an inlined or a generic body for which -- code is generated in other units may need to see these entities. Cut -- down the number of global symbols that do not neet public visibility -- as this has two beneficial effects: -- (1) It makes the compilation process more efficient. -- (2) It gives the code generator more leeway to optimize within each -- unit, especially subprograms. -- This is done only for top-level library packages or child units as -- the algorithm does a top-down traversal of the package body. if (Scope (Spec_Id) = Standard_Standard or else Is_Child_Unit (Spec_Id)) and then not Is_Generic_Unit (Spec_Id) then Hide_Public_Entities (Declarations (N)); 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; Ignore_SPARK_Mode_Pragmas_In_Instance := Saved_ISMP; Restore_Ghost_Mode (Saved_GM); end Analyze_Package_Body_Helper; --------------------------------- -- Analyze_Package_Declaration -- --------------------------------- procedure Analyze_Package_Declaration (N : Node_Id) is Id : constant Node_Id := Defining_Entity (N); Is_Comp_Unit : constant Boolean := Nkind (Parent (N)) = N_Compilation_Unit; Body_Required : Boolean; -- True when this package declaration requires a corresponding body begin if Debug_Flag_C then Write_Str ("==> package spec "); Write_Name (Chars (Id)); Write_Str (" from "); Write_Location (Sloc (N)); Write_Eol; Indent; end if; Generate_Definition (Id); Enter_Name (Id); Set_Ekind (Id, E_Package); Set_Etype (Id, Standard_Void_Type); -- Set SPARK_Mode from context Set_SPARK_Pragma (Id, SPARK_Mode_Pragma); Set_SPARK_Aux_Pragma (Id, SPARK_Mode_Pragma); Set_SPARK_Pragma_Inherited (Id); Set_SPARK_Aux_Pragma_Inherited (Id); -- Save the state of flag Ignore_SPARK_Mode_Pragmas_In_Instance in case -- the body of this package is instantiated or inlined later and out of -- context. The body uses this attribute to restore the value of the -- global flag. if Ignore_SPARK_Mode_Pragmas_In_Instance then Set_Ignore_SPARK_Mode_Pragmas (Id); end if; -- Analyze aspect specifications immediately, since we need to recognize -- things like Pure early enough to diagnose violations during analysis. if Has_Aspects (N) then Analyze_Aspect_Specifications (N, Id); end if; -- Ada 2005 (AI-217): Check if the package has been illegally named in -- a limited-with clause of its own context. In this case the error has -- been previously notified by Analyze_Context. -- limited with Pkg; -- ERROR -- package Pkg is ... if From_Limited_With (Id) then return; end if; Push_Scope (Id); Set_Is_Pure (Id, Is_Pure (Enclosing_Lib_Unit_Entity)); Set_Categorization_From_Pragmas (N); Analyze (Specification (N)); Validate_Categorization_Dependency (N, Id); -- Determine whether the package requires a body. Abstract states are -- intentionally ignored because they do require refinement which can -- only come in a body, but at the same time they do not force the need -- for a body on their own (SPARK RM 7.1.4(4) and 7.2.2(3)). Body_Required := Unit_Requires_Body (Id); if not Body_Required then -- If the package spec does not require an explicit body, then there -- are not entities requiring completion in the language sense. Call -- Check_Completion now to ensure that nested package declarations -- that require an implicit body get one. (In the case where a body -- is required, Check_Completion is called at the end of the body's -- declarative part.) Check_Completion; -- If the package spec does not require an explicit body, then all -- abstract states declared in nested packages cannot possibly get -- a proper refinement (SPARK RM 7.2.2(3)). This check is performed -- only when the compilation unit is the main unit to allow for -- modular SPARK analysis where packages do not necessarily have -- bodies. if Is_Comp_Unit then Check_State_Refinements (Context => N, Is_Main_Unit => Parent (N) = Cunit (Main_Unit)); end if; end if; -- Set Body_Required indication on the compilation unit node if Is_Comp_Unit then Set_Body_Required (Parent (N), Body_Required); end if; End_Package_Scope (Id); -- For the declaration of a library unit that is a remote types package, -- check legality rules regarding availability of stream attributes for -- types that contain non-remote access values. This subprogram performs -- visibility tests that rely on the fact that we have exited the scope -- of Id. if Is_Comp_Unit then Validate_RT_RAT_Component (N); end if; if Debug_Flag_C then Outdent; Write_Str ("<== package spec "); Write_Name (Chars (Id)); Write_Str (" from "); Write_Location (Sloc (N)); Write_Eol; 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; Private_With_Clauses_Installed : Boolean := False; -- In Ada 2005, private with_clauses are visible in the private part -- of a nested package, even if it appears in the public part of the -- enclosing package. This requires a separate step to install these -- private_with_clauses, and remove them at the end of the nested -- package. procedure Check_One_Tagged_Type_Or_Extension_At_Most; -- Issue an error in SPARK mode if a package specification contains -- more than one tagged type or type extension. 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_Unchecked_Union_Completion (Decls : List_Id); -- Reject completion of an incomplete or private type declarations -- having a known discriminant part by an unchecked union. procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id); -- Given the package entity of a generic package instantiation or -- formal package whose corresponding generic is a child unit, installs -- the private declarations of each of the child unit's parents. -- This has to be done at the point of entering the instance package's -- private part rather than being done in Sem_Ch12.Install_Parent -- (which is where the parents' visible declarations are installed). ------------------------------------------------ -- Check_One_Tagged_Type_Or_Extension_At_Most -- ------------------------------------------------ procedure Check_One_Tagged_Type_Or_Extension_At_Most is Previous : Node_Id; procedure Check_Decls (Decls : List_Id); -- Check that either Previous is Empty and Decls does not contain -- more than one tagged type or type extension, or Previous is -- already set and Decls contains no tagged type or type extension. ----------------- -- Check_Decls -- ----------------- procedure Check_Decls (Decls : List_Id) is Decl : Node_Id; begin Decl := First (Decls); while Present (Decl) loop if Nkind (Decl) = N_Full_Type_Declaration and then Is_Tagged_Type (Defining_Identifier (Decl)) then if No (Previous) then Previous := Decl; else Error_Msg_Sloc := Sloc (Previous); Check_SPARK_05_Restriction ("at most one tagged type or type extension allowed", "\\ previous declaration#", Decl); end if; end if; Next (Decl); end loop; end Check_Decls; -- Start of processing for Check_One_Tagged_Type_Or_Extension_At_Most begin Previous := Empty; Check_Decls (Vis_Decls); if Present (Priv_Decls) then Check_Decls (Priv_Decls); end if; end Check_One_Tagged_Type_Or_Extension_At_Most; --------------------- -- 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 may seem odd, but it is needed, because a -- package can contain a renaming declaration to itself, and such -- renamings are generated automatically within package instances. E := FE; while Present (E) and then E /= Id loop if Is_Assignable (E) then Set_Never_Set_In_Source (E, False); Set_Is_True_Constant (E, False); Set_Current_Value (E, Empty); Set_Is_Known_Null (E, False); Set_Last_Assignment (E, Empty); if not Can_Never_Be_Null (E) then Set_Is_Known_Non_Null (E, False); end if; elsif Is_Package_Or_Generic_Package (E) 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 not Nkind_In (Unit (Cunit (Main_Unit)), N_Subprogram_Body, 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_Unchecked_Union_Completion -- ---------------------------------------- procedure Inspect_Unchecked_Union_Completion (Decls : List_Id) is Decl : Node_Id; begin Decl := First (Decls); 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_In (Decl, N_Incomplete_Type_Declaration, 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; ----------------------------------------- -- Install_Parent_Private_Declarations -- ----------------------------------------- procedure Install_Parent_Private_Declarations (Inst_Id : Entity_Id) is Inst_Par : Entity_Id; Gen_Par : Entity_Id; Inst_Node : Node_Id; begin Inst_Par := Inst_Id; Gen_Par := Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par))); while Present (Gen_Par) and then Is_Child_Unit (Gen_Par) loop Inst_Node := Get_Unit_Instantiation_Node (Inst_Par); if Nkind_In (Inst_Node, N_Package_Instantiation, N_Formal_Package_Declaration) and then Nkind (Name (Inst_Node)) = N_Expanded_Name then Inst_Par := Entity (Prefix (Name (Inst_Node))); if Present (Renamed_Entity (Inst_Par)) then Inst_Par := Renamed_Entity (Inst_Par); end if; Gen_Par := Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par))); -- Install the private declarations and private use clauses -- of a parent instance of the child instance, unless the -- parent instance private declarations have already been -- installed earlier in Analyze_Package_Specification, which -- happens when a generic child is instantiated, and the -- instance is a child of the parent instance. -- Installing the use clauses of the parent instance twice -- is both unnecessary and wrong, because it would cause the -- clauses to be chained to themselves in the use clauses -- list of the scope stack entry. That in turn would cause -- an endless loop from End_Use_Clauses upon scope exit. -- The parent is now fully visible. It may be a hidden open -- scope if we are currently compiling some child instance -- declared within it, but while the current instance is being -- compiled the parent is immediately visible. In particular -- its entities must remain visible if a stack save/restore -- takes place through a call to Rtsfind. if Present (Gen_Par) then if not In_Private_Part (Inst_Par) then Install_Private_Declarations (Inst_Par); Set_Use (Private_Declarations (Specification (Unit_Declaration_Node (Inst_Par)))); Set_Is_Hidden_Open_Scope (Inst_Par, False); end if; -- If we've reached the end of the generic instance parents, -- then finish off by looping through the nongeneric parents -- and installing their private declarations. -- If one of the non-generic parents is itself on the scope -- stack, do not install its private declarations: they are -- installed in due time when the private part of that parent -- is analyzed. else while Present (Inst_Par) and then Inst_Par /= Standard_Standard and then (not In_Open_Scopes (Inst_Par) or else not In_Private_Part (Inst_Par)) loop if Nkind (Inst_Node) = N_Formal_Package_Declaration or else not Is_Ancestor_Package (Inst_Par, Cunit_Entity (Current_Sem_Unit)) then Install_Private_Declarations (Inst_Par); Set_Use (Private_Declarations (Specification (Unit_Declaration_Node (Inst_Par)))); Inst_Par := Scope (Inst_Par); else exit; end if; end loop; exit; end if; else exit; end if; end loop; end Install_Parent_Private_Declarations; -- Start of processing for Analyze_Package_Specification begin if Present (Vis_Decls) then Analyze_Declarations (Vis_Decls); end if; -- Inspect the entities defined in the package and ensure that all -- incomplete types have received full declarations. Build default -- initial condition and invariant procedures for all qualifying types. E := First_Entity (Id); while Present (E) loop -- Check on incomplete types -- AI05-0213: A formal incomplete type has no completion, and neither -- does the corresponding subtype in an instance. if Is_Incomplete_Type (E) and then No (Full_View (E)) and then not Is_Generic_Type (E) and then not From_Limited_With (E) and then not Is_Generic_Actual_Type (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 -- Insert the freezing nodes after the visible declarations to -- ensure that we analyze its aspects; needed to ensure that -- global entities referenced in the aspects are properly handled. if Ada_Version >= Ada_2012 and then Is_Non_Empty_List (Vis_Decls) and then Is_Empty_List (Priv_Decls) then Insert_List_After_And_Analyze (Last (Vis_Decls), Freeze_Entity (Id, Last (Vis_Decls))); end if; 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, it 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) and then In_Open_Scopes (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); else -- The current compilation unit may include private with_clauses, -- which are visible in the private part of the current nested -- package, and have to be installed now. This is not done for -- nested instantiations, where the private with_clauses of the -- enclosing unit have no effect once the instantiation info is -- established and we start analyzing the package declaration. declare Comp_Unit : constant Entity_Id := Cunit_Entity (Current_Sem_Unit); begin if Is_Package_Or_Generic_Package (Comp_Unit) and then not In_Private_Part (Comp_Unit) and then not In_Instance then Install_Private_With_Clauses (Comp_Unit); Private_With_Clauses_Installed := True; end if; end; end if; -- If this is a package associated with a generic instance or formal -- package, then the private declarations of each of the generic's -- parents must be installed at this point. if Is_Generic_Instance (Id) then Install_Parent_Private_Declarations (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's 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 (Priv_Decls); -- 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; E := First_Entity (Id); while Present (E) loop -- Check rule of 3.6(11), which in general requires waiting till all -- full types have been seen. if Ekind (E) = E_Record_Type or else Ekind (E) = E_Array_Type then Check_Aliased_Component_Types (E); end if; -- Check preelaborable initialization for full type completing a -- private type for which pragma Preelaborable_Initialization given. if Is_Type (E) and then Must_Have_Preelab_Init (E) and then not Has_Preelaborable_Initialization (E) then Error_Msg_N ("full view of & does not have preelaborable initialization", 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 -- Insert the freezing nodes after the private declarations to -- ensure that we analyze its aspects; needed to ensure that -- global entities referenced in the aspects are properly handled. if Ada_Version >= Ada_2012 and then Is_Non_Empty_List (Priv_Decls) then Insert_List_After_And_Analyze (Last (Priv_Decls), Freeze_Entity (Id, Last (Priv_Decls))); end if; 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); -- Remove private_with_clauses of enclosing compilation unit, if they -- were installed. if Private_With_Clauses_Installed then Remove_Private_With_Clauses (Cunit (Current_Sem_Unit)); end if; -- 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; -- Issue an error in SPARK mode if a package specification contains -- more than one tagged type or type extension. Check_One_Tagged_Type_Or_Extension_At_Most; -- Output relevant information as to why the package requires a body. -- Do not consider generated packages as this exposes internal symbols -- and leads to confusing messages. if List_Body_Required_Info and then In_Extended_Main_Source_Unit (Id) and then Unit_Requires_Body (Id) and then Comes_From_Source (Id) then Unit_Requires_Body_Info (Id); end if; -- Nested package specs that do not require bodies are not checked for -- ineffective use clauses due to the possbility of subunits. This is -- because at this stage it is impossible to tell whether there will be -- a separate body. if not Unit_Requires_Body (Id) and then Is_Compilation_Unit (Id) and then not Is_Private_Descendant (Id) then Update_Use_Clause_Chain; end if; end Analyze_Package_Specification; -------------------------------------- -- Analyze_Private_Type_Declaration -- -------------------------------------- procedure Analyze_Private_Type_Declaration (N : Node_Id) is Id : constant Entity_Id := Defining_Identifier (N); PF : constant Boolean := Is_Pure (Enclosing_Lib_Unit_Entity); begin Generate_Definition (Id); Set_Is_Pure (Id, PF); Init_Size_Align (Id); if not Is_Package_Or_Generic_Package (Current_Scope) 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); -- Set the SPARK mode from the current context Set_SPARK_Pragma (Id, SPARK_Mode_Pragma); Set_SPARK_Pragma_Inherited (Id); if Has_Aspects (N) then Analyze_Aspect_Specifications (N, Id); end if; end Analyze_Private_Type_Declaration; ---------------------------------- -- Check_Anonymous_Access_Types -- ---------------------------------- procedure Check_Anonymous_Access_Types (Spec_Id : Entity_Id; P_Body : Node_Id) is E : Entity_Id; IR : Node_Id; begin -- Itype references are only needed by gigi, to force elaboration of -- itypes. In the absence of code generation, they are not needed. if not Expander_Active then return; end if; E := First_Entity (Spec_Id); while Present (E) loop if Ekind (E) = E_Anonymous_Access_Type and then From_Limited_With (E) then IR := Make_Itype_Reference (Sloc (P_Body)); Set_Itype (IR, E); if No (Declarations (P_Body)) then Set_Declarations (P_Body, New_List (IR)); else Prepend (IR, Declarations (P_Body)); end if; end if; Next_Entity (E); end loop; end Check_Anonymous_Access_Types; ------------------------------------------- -- Declare_Inherited_Private_Subprograms -- ------------------------------------------- procedure Declare_Inherited_Private_Subprograms (Id : Entity_Id) is function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean; -- Check whether an inherited subprogram S is an operation of an -- untagged derived type T. --------------------- -- Is_Primitive_Of -- --------------------- function Is_Primitive_Of (T : Entity_Id; S : Entity_Id) return Boolean is Formal : Entity_Id; begin -- If the full view is a scalar type, the type is the anonymous base -- type, but the operation mentions the first subtype, so check the -- signature against the base type. if Base_Type (Etype (S)) = Base_Type (T) then return True; else Formal := First_Formal (S); while Present (Formal) loop if Base_Type (Etype (Formal)) = Base_Type (T) then return True; end if; Next_Formal (Formal); end loop; return False; end if; end Is_Primitive_Of; -- Local variables 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; Tag : Entity_Id; -- 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 Is_Base_Type (E) then if Is_Tagged_Type (E) then Op_List := Primitive_Operations (E); New_Op := Empty; Tag := First_Tag_Component (E); Op_Elmt := First_Elmt (Op_List); while Present (Op_Elmt) loop Prim_Op := Node (Op_Elmt); -- Search primitives that are implicit operations with an -- internal name whose parent operation has a normal name. if Present (Alias (Prim_Op)) and then Find_Dispatching_Type (Alias (Prim_Op)) /= E 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); -- Case 1: Check if the type has also an explicit -- overriding for this primitive. Op_Elmt_2 := Next_Elmt (Op_Elmt); while Present (Op_Elmt_2) loop -- Skip entities with attribute Interface_Alias since -- they are not overriding primitives (these entities -- link an interface primitive with their covering -- primitive) if Chars (Node (Op_Elmt_2)) = Chars (Parent_Subp) and then Type_Conformant (Prim_Op, Node (Op_Elmt_2)) and then No (Interface_Alias (Node (Op_Elmt_2))) then -- The private inherited operation has been -- overridden by an explicit subprogram: -- replace the former by the latter. New_Op := Node (Op_Elmt_2); Replace_Elmt (Op_Elmt, New_Op); Remove_Elmt (Op_List, Op_Elmt_2); Set_Overridden_Operation (New_Op, Parent_Subp); -- We don't need to inherit its dispatching slot. -- Set_All_DT_Position has previously ensured that -- the same slot was assigned to the two primitives if Present (Tag) and then Present (DTC_Entity (New_Op)) and then Present (DTC_Entity (Prim_Op)) then pragma Assert (DT_Position (New_Op) = DT_Position (Prim_Op)); null; end if; goto Next_Primitive; end if; Next_Elmt (Op_Elmt_2); end loop; -- Case 2: We have not found any explicit overriding and -- hence we need to declare the operation (i.e., make it -- visible). Derive_Subprogram (New_Op, Alias (Prim_Op), E, Etype (E)); -- Inherit the dispatching slot if E is already frozen if Is_Frozen (E) and then Present (DTC_Entity (Alias (Prim_Op))) then Set_DTC_Entity_Value (E, New_Op); Set_DT_Position_Value (New_Op, DT_Position (Alias (Prim_Op))); end if; 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); end if; <> Next_Elmt (Op_Elmt); end loop; -- Generate listing showing the contents of the dispatch table if Debug_Flag_ZZ then Write_DT (E); end if; else -- For untagged 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); -- Derived operations appear immediately after the type -- declaration (or the following subtype indication for -- a derived scalar type). Further declarations cannot -- include inherited operations of the type. if Present (Prim_Op) then exit when Ekind (Prim_Op) not in Overloadable_Kind; end if; 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 Is_Child_Unit (Id) then null; -- Do not enter implicitly inherited non-overridden subprograms of -- a tagged type back into visibility if they have non-conformant -- homographs (Ada RM 8.3 12.3/2). elsif Is_Hidden_Non_Overridden_Subpgm (Id) then null; else 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; Full : Entity_Id; Priv_Deps : Elist_Id; procedure Swap_Private_Dependents (Priv_Deps : Elist_Id); -- When the full view of a private type is made available, we do the -- same for its private dependents under proper visibility conditions. -- When compiling a grand-chid unit this needs to be done recursively. ----------------------------- -- Swap_Private_Dependents -- ----------------------------- procedure Swap_Private_Dependents (Priv_Deps : Elist_Id) is Deps : Elist_Id; Priv : Entity_Id; Priv_Elmt : Elmt_Id; Is_Priv : Boolean; begin Priv_Elmt := First_Elmt (Priv_Deps); while Present (Priv_Elmt) loop Priv := Node (Priv_Elmt); -- Before the exchange, verify that the presence of the Full_View -- field. This field 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 if Is_Private_Type (Priv) then Deps := Private_Dependents (Priv); Is_Priv := True; else Is_Priv := False; end if; -- 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)); -- Ensure that both views of the dependent private subtype are -- immediately visible if within some open scope. Check full -- view before exchanging views. if In_Open_Scopes (Scope (Full_View (Priv))) then Set_Is_Immediately_Visible (Priv); end if; 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))); -- Within a child unit, recurse, except in generic child unit, -- which (unfortunately) handle private_dependents separately. if Is_Priv and then Is_Child_Unit (Cunit_Entity (Current_Sem_Unit)) and then not Is_Empty_Elmt_List (Deps) and then not Inside_A_Generic then Swap_Private_Dependents (Deps); end if; end if; Next_Elmt (Priv_Elmt); end loop; end Swap_Private_Dependents; -- Start of processing for Install_Private_Declarations 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 Present (Full_View (Id)) and then Comes_From_Source (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. -- Save the current full view as well, so that all views can be -- restored on exit. It may seem that after compiling the child -- body there are not environments to restore, but the back-end -- expects those links to be valid, and freeze nodes depend on -- them. 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 (Id, Full); Set_Is_Underlying_Full_View (Full); Set_Underlying_Full_View (Full, Empty); Set_Is_Frozen (Full_View (Id)); end if; end if; Priv_Deps := Private_Dependents (Id); Exchange_Declarations (Id); Set_Is_Immediately_Visible (Id); Swap_Private_Dependents (Priv_Deps); 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; -- An abstract state is partially refined when it has at least one -- Part_Of constituent. Since these constituents are being installed -- into visibility, update the partial refinement status of any state -- defined in the associated package, subject to at least one Part_Of -- constituent. if Ekind_In (P, E_Generic_Package, E_Package) then declare States : constant Elist_Id := Abstract_States (P); State_Elmt : Elmt_Id; State_Id : Entity_Id; begin if Present (States) then State_Elmt := First_Elmt (States); while Present (State_Elmt) loop State_Id := Node (State_Elmt); if Present (Part_Of_Constituents (State_Id)) then Set_Has_Partial_Visible_Refinement (State_Id); end if; Next_Elmt (State_Elmt); end loop; end if; end; end if; -- 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; Last_Entity : Entity_Id; begin pragma Assert (Is_Package_Or_Generic_Package (P) or else Is_Record_Type (P)); if Is_Package_Or_Generic_Package (P) then Last_Entity := First_Private_Entity (P); else Last_Entity := Empty; end if; Id := First_Entity (P); while Present (Id) and then Id /= Last_Entity 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)) or else Has_RACW (E)) 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 -- For other than Ada 2012, enter the name in the current scope if Ada_Version < Ada_2012 then Enter_Name (Id); -- Ada 2012 (AI05-0162): Enter the name in the current scope. Note that -- there may be an incomplete previous view. else declare Prev : Entity_Id; begin Prev := Find_Type_Name (N); pragma Assert (Prev = Id or else (Ekind (Prev) = E_Incomplete_Type and then Present (Full_View (Prev)) and then Full_View (Prev) = Id)); end; end if; 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 Push_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); Set_Direct_Primitive_Operations (Id, New_Elmt_List); Set_Is_Abstract_Type (Id, Abstract_Present (Def)); Set_Is_Limited_Record (Id, Limited_Present (Def)); Set_Has_Delayed_Freeze (Id, True); -- Recognize Ada.Real_Time.Timing_Events.Timing_Events here if Is_RTE (Id, RE_Timing_Event) then Set_Has_Timing_Event (Id); end if; -- Create a class-wide type with the same attributes Make_Class_Wide_Type (Id); elsif Abstract_Present (Def) then Error_Msg_N ("only a tagged type can be abstract", N); end if; end New_Private_Type; --------------------------------- -- Requires_Completion_In_Body -- --------------------------------- function Requires_Completion_In_Body (Id : Entity_Id; Pack_Id : Entity_Id; Do_Abstract_States : Boolean := False) return Boolean is begin -- 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 (Id) then return False; -- Ignore formal packages and their renamings elsif Ekind (Id) = E_Package and then Nkind (Original_Node (Unit_Declaration_Node (Id))) = N_Formal_Package_Declaration then return False; -- Otherwise test to see if entity requires a completion. Note that -- subprogram entities whose declaration does not come from source are -- ignored here on the basis that we assume the expander will provide an -- implicit completion at some point. elsif (Is_Overloadable (Id) and then not Ekind_In (Id, E_Enumeration_Literal, E_Operator) and then not Is_Abstract_Subprogram (Id) and then not Has_Completion (Id) and then Comes_From_Source (Parent (Id))) or else (Ekind (Id) = E_Package and then Id /= Pack_Id and then not Has_Completion (Id) and then Unit_Requires_Body (Id, Do_Abstract_States)) or else (Ekind (Id) = E_Incomplete_Type and then No (Full_View (Id)) and then not Is_Generic_Type (Id)) or else (Ekind_In (Id, E_Task_Type, E_Protected_Type) and then not Has_Completion (Id)) or else (Ekind (Id) = E_Generic_Package and then Id /= Pack_Id and then not Has_Completion (Id) and then Unit_Requires_Body (Id, Do_Abstract_States)) or else (Is_Generic_Subprogram (Id) and then not Has_Completion (Id)) then return True; -- Otherwise the entity does not require completion in a package body else return False; end if; end Requires_Completion_In_Body; ---------------------------- -- 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 : Entity_Id; 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 : Entity_Id; Full : Entity_Id) is Full_Base : constant Entity_Id := Base_Type (Full); Priv_Is_Base_Type : constant Boolean := Is_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)); Set_Is_Ada_2005_Only (Priv, Is_Ada_2005_Only (Full)); Set_Is_Ada_2012_Only (Priv, Is_Ada_2012_Only (Full)); Set_Has_Pragma_Unmodified (Priv, Has_Pragma_Unmodified (Full)); Set_Has_Pragma_Unreferenced (Priv, Has_Pragma_Unreferenced (Full)); Set_Has_Pragma_Unreferenced_Objects (Priv, Has_Pragma_Unreferenced_Objects (Full)); if Is_Unchecked_Union (Full) then Set_Is_Unchecked_Union (Base_Type (Priv)); end if; -- Why is atomic not copied here ??? if Referenced (Full) then Set_Referenced (Priv); end if; if Priv_Is_Base_Type then Set_Is_Controlled_Active (Priv, Is_Controlled_Active (Full_Base)); Set_Finalize_Storage_Only (Priv, Finalize_Storage_Only (Full_Base)); Set_Has_Controlled_Component (Priv, Has_Controlled_Component (Full_Base)); Propagate_Concurrent_Flags (Priv, Base_Type (Full)); end if; Set_Freeze_Node (Priv, Freeze_Node (Full)); -- Propagate Default_Initial_Condition-related attributes from the -- base type of the full view to the full view and vice versa. This -- may seem strange, but is necessary depending on which type -- triggered the generation of the DIC procedure body. As a result, -- both the full view and its base type carry the same DIC-related -- information. Propagate_DIC_Attributes (Full, From_Typ => Full_Base); Propagate_DIC_Attributes (Full_Base, From_Typ => Full); -- Propagate Default_Initial_Condition-related attributes from the -- full view to the private view. Propagate_DIC_Attributes (Priv, From_Typ => Full); -- Propagate invariant-related attributes from the base type of the -- full view to the full view and vice versa. This may seem strange, -- but is necessary depending on which type triggered the generation -- of the invariant procedure body. As a result, both the full view -- and its base type carry the same invariant-related information. Propagate_Invariant_Attributes (Full, From_Typ => Full_Base); Propagate_Invariant_Attributes (Full_Base, From_Typ => Full); -- Propagate invariant-related attributes from the full view to the -- private view. Propagate_Invariant_Attributes (Priv, From_Typ => Full); if Is_Tagged_Type (Priv) and then Is_Tagged_Type (Full) and then not Error_Posted (Full) then if Is_Tagged_Type (Priv) then -- If the type is tagged, the tag itself must be available on -- the partial view, for expansion purposes. Set_First_Entity (Priv, First_Entity (Full)); -- If there are discriminants in the partial view, these remain -- visible. Otherwise only the tag itself is visible, and there -- are no nameable components in the partial view. if No (Last_Entity (Priv)) then Set_Last_Entity (Priv, First_Entity (Priv)); end if; end if; Set_Has_Discriminants (Priv, Has_Discriminants (Full)); if Has_Discriminants (Full) then Set_Discriminant_Constraint (Priv, Discriminant_Constraint (Full)); end if; 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 if In_Use (P) and then not Is_Hidden (Id) then -- A child unit of a use-visible package remains use-visible -- only if it is itself a visible child unit. Otherwise it -- would remain visible in other contexts where P is use- -- visible, because once compiled it stays in the entity list -- of its parent unit. if Is_Child_Unit (Id) then Set_Is_Potentially_Use_Visible (Id, Is_Visible_Lib_Unit (Id)); else Set_Is_Potentially_Use_Visible (Id); end if; else Set_Is_Potentially_Use_Visible (Id, False); end if; 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. Similarly, ensure that the -- use-visibility is properly set on both views. if Is_Type (Id) and then Present (Full_View (Id)) then Set_Is_Immediately_Visible (Full_View (Id), False); Set_Is_Potentially_Use_Visible (Full_View (Id), Is_Potentially_Use_Visible (Id)); end if; if Is_Tagged_Type (Id) and then Ekind (Id) = E_Record_Type then Check_Abstract_Overriding (Id); Check_Conventions (Id); end if; if Ekind_In (Id, E_Private_Type, 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; -- Case of constant, check for deferred constant declaration with -- no full view. Likely just a matter of a missing expression, or -- accidental use of the keyword constant. elsif Ekind (Id) = E_Constant -- OK if constant value present and then No (Constant_Value (Id)) -- OK if full view present and then No (Full_View (Id)) -- OK if imported, since that provides the completion and then not Is_Imported (Id) -- OK if object declaration replaced by renaming declaration as -- a result of OK_To_Rename processing (e.g. for concatenation) and then Nkind (Parent (Id)) /= N_Object_Renaming_Declaration -- OK if object declaration with the No_Initialization flag set and then not (Nkind (Parent (Id)) = N_Object_Declaration and then No_Initialization (Parent (Id))) then -- If no private declaration is present, we assume the user did -- not intend a deferred constant declaration and the problem -- is simply that the initializing expression is missing. if not Has_Private_Declaration (Etype (Id)) then -- We assume that the user did 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 ("\if variable intended, remove CONSTANT from declaration", Parent (Id)); end if; -- Otherwise if a private declaration is present, then we are -- missing the full declaration for the deferred constant. else Error_Msg_N ("missing full declaration for deferred constant (RM 7.4)", Id); if Is_Limited_Type (Etype (Id)) then Error_Msg_N ("\if variable intended, remove 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. Id is now the first private entity -- in the package. 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); Check_Conventions (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)); -- The following test may be redundant, as this is already -- diagnosed in sem_ch3. ??? if not Is_Definite_Subtype (Full) and then Is_Definite_Subtype (Id) then Error_Msg_Sloc := Sloc (Parent (Id)); Error_Msg_NE ("full view of& not compatible with declaration#", Full, Id); end if; -- 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). Priv_Elmt := First_Elmt (Private_Dependents (Id)); 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); -- If we have installed an underlying full view for a type derived -- from a private type in a child unit, restore the proper views -- of private and full view. See corresponding code in -- Install_Private_Declarations. -- After the exchange, Full denotes the private type in the -- visible part of the package. if Is_Private_Base_Type (Full) and then Present (Full_View (Full)) and then Present (Underlying_Full_View (Full)) and then In_Package_Body (Current_Scope) then Set_Full_View (Full, Underlying_Full_View (Full)); Set_Underlying_Full_View (Full, Empty); end if; elsif Ekind (Id) = E_Incomplete_Type and then Comes_From_Source (Id) and then No (Full_View (Id)) then -- Mark Taft amendment types. Verify that there are no primitive -- operations declared for the type (3.10.1(9)). Set_Has_Completion_In_Body (Id); declare Elmt : Elmt_Id; Subp : Entity_Id; begin Elmt := First_Elmt (Private_Dependents (Id)); while Present (Elmt) loop Subp := Node (Elmt); -- Is_Primitive is tested because there can be cases where -- nonprimitive subprograms (in nested packages) are added -- to the Private_Dependents list. if Is_Overloadable (Subp) and then Is_Primitive (Subp) then Error_Msg_NE ("type& must be completed in the private part", Parent (Subp), Id); -- The result type of an access-to-function type cannot be a -- Taft-amendment type, unless the version is Ada 2012 or -- later (see AI05-151). elsif Ada_Version < Ada_2012 and then Ekind (Subp) = E_Subprogram_Type then if Etype (Subp) = Id or else (Is_Class_Wide_Type (Etype (Subp)) and then Etype (Etype (Subp)) = Id) then Error_Msg_NE ("type& must be completed in the private part", Associated_Node_For_Itype (Subp), Id); end if; end if; Next_Elmt (Elmt); end loop; end; 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 (Pack_Id : Entity_Id; Do_Abstract_States : Boolean := False) return Boolean is E : Entity_Id; Requires_Body : Boolean := False; -- Flag set when the unit has at least one construct that requries -- completion in a body. 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 (Pack_Id) then return False; -- Body required if library package with pragma Elaborate_Body elsif Has_Pragma_Elaborate_Body (Pack_Id) then return True; -- Body required if subprogram elsif Is_Subprogram_Or_Generic_Subprogram (Pack_Id) then return True; -- Treat a block as requiring a body elsif Ekind (Pack_Id) = E_Block then return True; elsif Ekind (Pack_Id) = E_Package and then Nkind (Parent (Pack_Id)) = N_Package_Specification and then Present (Generic_Parent (Parent (Pack_Id))) then declare G_P : constant Entity_Id := Generic_Parent (Parent (Pack_Id)); begin if Has_Pragma_Elaborate_Body (G_P) then return True; end if; end; end if; -- Traverse the entity chain of the package and look for constructs that -- require a completion in a body. E := First_Entity (Pack_Id); while Present (E) loop -- Skip abstract states because their completion depends on several -- criteria (see below). if Ekind (E) = E_Abstract_State then null; elsif Requires_Completion_In_Body (E, Pack_Id, Do_Abstract_States) then Requires_Body := True; exit; end if; Next_Entity (E); end loop; -- A [generic] package that defines at least one non-null abstract state -- requires a completion only when at least one other construct requires -- a completion in a body (SPARK RM 7.1.4(4) and (6)). This check is not -- performed if the caller requests this behavior. if Do_Abstract_States and then Ekind_In (Pack_Id, E_Generic_Package, E_Package) and then Has_Non_Null_Abstract_State (Pack_Id) and then Requires_Body then return True; end if; return Requires_Body; end Unit_Requires_Body; ----------------------------- -- Unit_Requires_Body_Info -- ----------------------------- procedure Unit_Requires_Body_Info (Pack_Id : Entity_Id) is E : Entity_Id; begin -- An 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 (Pack_Id) then return; -- Body required if library package with pragma Elaborate_Body elsif Has_Pragma_Elaborate_Body (Pack_Id) then Error_Msg_N ("info: & requires body (Elaborate_Body)?Y?", Pack_Id); -- Body required if subprogram elsif Is_Subprogram_Or_Generic_Subprogram (Pack_Id) then Error_Msg_N ("info: & requires body (subprogram case)?Y?", Pack_Id); -- Body required if generic parent has Elaborate_Body elsif Ekind (Pack_Id) = E_Package and then Nkind (Parent (Pack_Id)) = N_Package_Specification and then Present (Generic_Parent (Parent (Pack_Id))) then declare G_P : constant Entity_Id := Generic_Parent (Parent (Pack_Id)); begin if Has_Pragma_Elaborate_Body (G_P) then Error_Msg_N ("info: & requires body (generic parent Elaborate_Body)?Y?", Pack_Id); end if; end; -- A [generic] package that introduces at least one non-null abstract -- state requires completion. However, there is a separate rule that -- requires that such a package have a reason other than this for a -- body being required (if necessary a pragma Elaborate_Body must be -- provided). If Ignore_Abstract_State is True, we don't do this check -- (so we can use Unit_Requires_Body to check for some other reason). elsif Ekind_In (Pack_Id, E_Generic_Package, E_Package) and then Present (Abstract_States (Pack_Id)) and then not Is_Null_State (Node (First_Elmt (Abstract_States (Pack_Id)))) then Error_Msg_N ("info: & requires body (non-null abstract state aspect)?Y?", Pack_Id); end if; -- Otherwise search entity chain for entity requiring completion E := First_Entity (Pack_Id); while Present (E) loop if Requires_Completion_In_Body (E, Pack_Id) then Error_Msg_Node_2 := E; Error_Msg_NE ("info: & requires body (& requires completion)?Y?", E, Pack_Id); end if; Next_Entity (E); end loop; end Unit_Requires_Body_Info; end Sem_Ch7;